I

Data from the

NATIONAL HEALTH SURVEY

Skeletal Maturity of

Children 6-11 Years

United States

Skeletal age (hand-wrist), onset of ossification, and bone-specific

skeletal ages by chronological age and sex of boys and girls 6-11

years of age as assessed by the Health Examination Survey

Standard based primarily on the Greulich-Pyle Radiographic

Atlas.

DHEW Publication No. (HRA) 75-1622

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

Public Health Service

Series 11

Number 140

Health Resources Administration

National Center for Health Statistics

Rockville, Md. November 1974
Series 11 reports present findings from the National Health Examination Survey, which

obtains data through direct examination, tests, and measurements of samples of the U.S.

population. Reports 1 through 38 relate to the adult program, Cycle I of the Health

Examination Survey. The present report is one of a number of reports of findings from the

children and youth programs, Cycles II and III of the Health Examination Survey. These

latter reports from Cycles II and 111 are being published in Series 11 but are numbered

consecutively beginning with 101. It is hoped this will guide users to the data in which they

are interested.

*

.1 —

Library of Congress Cataloging in Publication Data

Roche, Alex. F.

Skeletal maturity of children 6-11 years, United States.

(National Center for Health Statistics. Data from the National Health Survey, series 11,

no. 140) (DHEW publication no. (HRA) 75-1622)

Supt. of Dots. no.: HE 20.2210: 11/140.

Bibliography: p.

1. Bone–Growth. 2. Ossification. 3. Sex differences. 4. United States–Statistics, Medical 1. Roberts, Jean, joint author. II. Hamill, Peter V. V., joint author. III. Title IV. Series:

United States. National Center for Health Statistics. Vital and health statistics. Series 11:

Data from the National Health Survey. Data from the health examination survey, no. 140. V.

Series: United States. Dept. of Health, Education, and Welfare. DHEW publication no. (HRA)

75-1622. [DNLM: 1. Age determination by skeleton–In infancy & childhood. 2. Bone development–In infancy & childhood. W2A N148vk no. 140 1974]

RA407.3.A347 no. 140 [RJ131] 312’.0973s [612’.75]

ISBN 0-8406-0006-2 74-3219

For ssle by the Superintendent of Documents, U.S. (government Printing Office, Washington, D .C. 20402- Price $1.25
NATIONAL CENTER FOR HEALTH STATISTICS

EDWARD B. PERRIN, Ph. D., Dkctor

PHI LIP S. LAWRENCE, SC.D., Deputy Director

JACOB J. FELDMAN, Ph. D., Acting Associate Director for An@Jsis

GAIL F. FISHER, Associate Director for the Cooperative Health Statistics System

ELIJAH L. WHITE, Associate Director for Data Systems

IWAO M. MORIYAMA, Ph. D., Associate Director for Interna tionul Statktics

EDWARD E, MINTY, Associate Direc tor for Managemen t

ROBERT A. ISRAEL, Associate Director for Operations

QUENTIN R. REMEIN, Associate Directorfor Program Development

PAUL E. LEAVERTON, Ph. D., A ctirzg Associate Director for Research

ALICE HAYWOOD, Information Officer

DIVISION OF HEALTH EXAMINATION STATISTICS

ARTHUR J. McDOWELL, Director

PETER V. V. HAMILL, M.D.. hledical Advisor, Children and Youth Programs

JEAN ROBERTS, Chiej Medical Statistics Branch

HENRY MILLER, Chiej Operations ~ranch

COOPERATION OF THE BUREAU OF THE CENSUS

In accordance with specifications established by the National

Center for Health Statistics, the Bureau of the Census, under a

contractual agreement, participated in the design and selection of

the sample, and carried out the first stage of the field interviewing

and certain parts of the statistical processing.

Vital and Health Statistics-Series 1 l-No. 140

DHEW Publication No. (HRA) 75-1622

Library of Congress Catalog Chrd Number 743219
CONTENTS

Page

Introduction ----------------------------------------------------------

TheNatureof Skeletal Maturation ---------------------------------------

Histolo@cal Chmges ------------------------------------------------

Radiographic Ch~ges -----------------------------------------------

Scale of Maturi~---------------------------------------------------

The Health Examination Survey Standard -------------------- --------------

Methods ---------------------------- ---------- “--------- --------------

Field Radiography --------------------------------------------------

Training ofAssessors --------.-------” ---------- --------------------

Assessment Procedure ----------------------------------------------

Findings -------------------------------------------------------------

Skeletal Age (Hand-Wrist) ---------------------------- ----------------

Onset of Ossification -.--.”-” -------- ------------------------- --------

Bone-SpecificSkeletal Ages ---------------- ------------------------ --

Discussion -----------------------------------------------------------

TheNeed fora Survey -.-” ----- ----m---- “---”---- --------------------

Skeletal Age (Hand-Wrist) .,------------------ --.---”-------” ----------

Onset of Ossification --.- . . ..”-------- ------------------------ -------”

Bone-Specific Skeletal Ages------------------------------------------

Ranges of Bone-Specific Skeletal Ages --------- ----.-----.--,----- --------

Sex-Associated Differences in Skeletal Maturi~------------------------

Other Measures of Biological Age------------------------ ------------

Summary -------------------------------------------------------------

References -----------------------------------------------------------

List of Detailed Tables -------------------------------------------------

Appendix 1. Statistical Notes ------”--- ------q-- ----------------------

TheSurveyDesign --------------------------- . ..-.--------” ---------

Reliability ----.” --------------------- .-.”” ---------------------- ---

Sampling and Measurement Error -------------------- -------.---------”

Small Categories -----,... -------- -------- ---------------- -------- ---

Appendix II. Reliability of Assessment --------------------------- ------

Area SkeletalAges --------------------------------------------------

Bone-SpecificSkeletal Ages --------------------------- ---------------

Factors Influencing Replicability --------------------------- ----------

1

2

2

5

6

7

8

8

8

9

10

10

17

19

23

24

24

25

26

26

27

28

29

30

35

57

57

57

58

59

60

62

62

62

...

.J 11.
SYMBOLS

Data not available--------------------------------------- ---

Category not applicable ------------------------------ . . .

Quantity zero --------------------------------------------- -

Quantity more than Obut less than 0.05---- 0.0

Figure does not meet standards of

reliability or precision ----------------------------

*

iv
SKELETALMATURITY OF CHILDREN

6-11 YEARS

A. F. Roche, M.D., FeIs Research Institute, and Jean Roberts and Peter V. V. Hamill, M.D.,

Dkirion of Health Examination Statistics

INTRODUCTION

This report presents national estimates of

the levels of skeletal maturity of the hand-wrist

for noninstitutionalized United States children

age 6-11 years based on findings from the Health

Examination Survey of 1963-65. This is the first

time that such estimates for a cross-section of

the population have been made for this or any

other country,

The Health Examination Survey is one of the

major programs of the National Center for Health

Statistics, authorized under the National Health

Survey Act of 1956 by the 84th Congress as a

continuing Public Health Service function to determine the health status of the population.

Three different types of survey programs are

used to carry out the intent of the National Health

Survey. 1The Health Interview Survey, which collects health information from samples of people

by household interview, is focused primarily on

the impact of illness and disability within various

population groups. The Health Resources programs obtain health data as well as health resource and utilization information through surveys

of hospitals, nursing homes and other resident.

institutions, and the entire range. of personnel in

the health occupations. The Health Examination

Survey, from which data in this report were obtained, collects health data by direct physical examination, tests, and measurements performed

on samples of the population. The latter program

provides the best way of obtaining actual diagnostic

data on the prevalence of certain medically defined

illnesses. It is the only effective way to secure

information on unrecognized and undiagnosed conditions and on a variety of physical, physiological,

and psychological measures within the population.

It also collects demographic and socioeconomic

data on the sample population understudy to which

the examination findings may be related.

The Health Examination Survey is organized

as a series of separate programs or cycles, each

of which is limited to some specific segment of

the U.S. population and to specific aspects of

health. From data collected during the first cycle,

the prevalence of certain chronic diseases and

the distribution of various physical and physiological measures were determined on a crosssection of the defined adult population as previously described.2’3

For the second cycle, the program on which

this report is based, a probability sample of the

noninstitutionalized children 6-11 years of age

in the United States was selected and examined.

The examination in this cross-sectional study

primarily assessed health factors related to

growth and development. It included an examination by a pediatrician and by a dentist, tests

administered by a psychologist, and a variety of

tests and measurements by a technician. The

survey plan, sample design, examination content,

and operation of the survey have been described

in a previous report. 4

Field collection operations for this cycle,

which started in July 1963, were completed in

December 1965. Of the 7,417 selected in the sample, 7,119 children, or 96 percent, were examined.

This national sample is closely representative

of the roughly 24 million noninstitutionalized

1
children 6-11 years of age in the United States

with, respect to age> sex, race, region, Size of

place of residence, and rate of change in size of

place of residence from 1950 to 1960. Of the children examined, there were an additional 157 who

were not radiographed or whose radiograph, taken

at the time of the survey, was not suitable for

assessment. Thus the skeletal maturity estimates

for United States children 6-11 years of age are

based on the remaining 6,962 children or 94 percent of the original sample.

Du.i-i,lg his single visit, each child was given

a standardized examination by the examining team

in the mobile units specially designed for use in

the survey. Prior to this examination, demographic and socioeconomic data on household

memjers as well as medical history, behavioral,

and related data on the child to be examined were

obtained from his parents. Ancillary data were

requested from the school attended by the child;

these included his grade placement, teacher’s

ratings of his behavior and adjustment, and

health problems known to his teacher. A birth

certificate for each child was obtained for verification of his age and information related to his

condition at birth.

Some measure of skeletal age or maturation

was considered essential to this study of health

factors related to normial growth and development

of children. Advice of clinicians and directors of

long-term studies of skeletal development was

obtained about possible uses of skeletal maturity

levels and methods of assessing skeletal age from

radiographs. Drs. William Walter Greulich and

Harold C. Stuart —the directors of growth studies

conducted independently from 1929 to 1962 at the

Brush Foundation in Cleveland, Ohio, and the

Department of Maternal and Child Health at

Harvard University in Boston, Massachusetts—

recommended that Dr. S. Idell Pyle assemble a

standard for the assessment of skeletal maturity

from :heir film series and studies, 5 specifically

for ‘use in the National Health Examination Survey.

At the formal request of the National Center

for Health Statistics the 1964 manual--a preliminary edition of the Radiographic Standard of Reference for the Growing Hand and Wrist 6—was

then prepared for this purpose by Dr. Pyle and

Dr. Greulich, in collaboration with Dr. Alice

Waterhouse, then Medical Advisor to the National

Center for Health Statistics. This manual will be

referred to in this report as the HES Standard.

Bone-specific skeletal age assessments of the

hand-wrist radiographs were done by m,~dical

students with special training in this method, at

Case Western Reserve University under the close

supervision of Dr. Pyle.

Statistical notes on the sample design, reliability of the data, and sampling error are in

appendix I.

THE NATURE OF

SKELETAL MATURATION

It is difficult to describe the nature of skeletal

maturation because knowledge of its recognizable

criteria is incomplete. A wealth of histological

detail has been reported concerning skeletal elongation but there is a surprising lack of corm+

spending knowledge concerning skeletal mXura -

tion. Furthermore, some of the literature indicates a failure to distinguish between elongation

and maturation of the skeleton at the histolo~ical

and radiographic levels. It is customary to consider that the skeleton begins to mature when

skeletal rudiments can be recognized first in the

embryo and that maturation is complete when

comparative stability of skeletal form and function

is attained in young adulthood. During maturation,

the number of specialized cells increases and

biochemical mechanisms become more complex.

The skeletal changes after young adulthood, par-

. titularly during senescence, include a reduction

in the number of specialized cells and therefore

can be described reasonably as a negative phase

of maturation.

Histological Changes

Maturation of a long bone commences when

some embryonic connective tissue in a Iimh bud

condenses to form a model.7 In the early models

of most, long bones, the parts that represent the

future diaphyses (shafts) are small relative to the

epiphyseal parts although the junctions between

these parts cannot be identified precisely.s The

condensed connective tissue of the model is replaced by cartilage; this’ occurs first in the central part of each model. 9 The connective tissue

2
around this cartilage becomes a well-defined

layer called the perichondrium. The outer layer

of this perichondrium differentiates to fibrous

tissue; the inner layer contains cells that can

mature into chondrocytes or osteocytes. The

cartilaginous models resemble in shape the adult

bones they precede: 0’1lThe models for two or

more adjacent bones are joined by connective

tissue in the regions of future joints; joint cavities form later. 9 The cartilagino~s models enlarge by apposition from the perichondrium, from

the connective tissue related to their ends, and by

the division of chondrocytes within the model. 9

The chondrocytes in the central parts of the

The later calcification of this area 14~15constitutes a phase of maturation. When this calcified

area is sufficiently large, it becomes radio.

opaque. This is the first stage of skeletal maturatio.~ that can be observed radiographically.

The area of hypertrophic chondrocytes and the

area of calcified cartilage enlarge more rapidly

than the model. This is shown by extension of

the hypertrophic and calcified areas along the

model (figure 1-B). Ossification begins when a

collar of bone forms deep to the perichondrium

around the central part of the cartilagino~s model

(figure l-B). Soon after this, ossification begins

in the central part of the model by replacement

models hypertrophy and vacuolize at about the of calcified cartilage (figure 1-C). This endosixth prenatal week {as shown in figure 1-A)?’l2’13

1( \/,..—

i!

h‘ ,,

. ,+, ,

.

PCarkilage

A B c

D E F G

NOTE r .m Rack,>, A c. T!;. e!o.gat i.,) of tho mandible, Am J Orthoct 53.79.94,

1367

Figure 1. A diagram of the maturation of a long bone in which

the length of the bone has been kept constant. The approximate age scale is: A, 6 weeks prenatal; B, 7 weeks prenatal;

C, 12 weeks prenatal; D, 16 weeks prenatal to 2 years; E, 2

to 6 years; F, 6 to 16 yaars; and G, adulthood. The clear area

in D-G representsthe marrow cavity.

chondral ossification begins where” cartilage first

~ormed. 9>16-I 8

The early stages of endochondral and subperiosteal ossification cannot be distinguished

radiographically. Soon these areas unite; later

their interrelationships become more complex

as a result of remodeling that continues throttgh -

out life. *9 The ossified areas extend along the

cartilaginous model both centraIIy (endochondraI)

and on its surface (subperiosteal). Endochondral

ossification occurs in areas where cartilage cells

have hypertrophied, the matrix has calcified, and

blood vessels, connective tissue cells, and osteoblasts are present. I 3 Subperiosteal ossification

extends along che cartilaginous model at about the

same rate as endochondral ossification. Both endochondral and subperiosteal ossification extend

along the model until they reach the future epiphyseal zones a (epiphyseo-diaphyseal junctions)

at each end of the model (figure 1-D). After this

stage of maturation has been reached, it is customary to refer to the ossified area as the diaphysis or shaft of the bone. Before this occurs,

a marrow cavity forms by resorption in the central part of the ossified area. This stage of maturation is not suitable for inclusion in a method

of assessment based on radiographs. For a considerable period after the diaphysis reaches the

ephiphyseal zones, a the ossified area does not

aThe term epiphyseal zone refers to the partofthe bone between the epiphysis and diaphysis. It is only applicable after the

epjphysk has be~n to ossi$—between the time when the ePiP]lysrs has started to ossify to the time when the epiphysis has

fused to the diaphysis. A bone with an epiphysis at each end

has two such zones; some other bones have only one.

3
extend further in relation to the total length of

the bone but changes that are visible radiographically occur in the shape of theend of the

diaphysis.

From the viewpoint of assessment, a most

important stage of maturation occurs when epiphyseal centers of ossification form within the

cartilage near the end of the diaphysis (figure

1-E). This occurs near each end of the diaphysis

of every long bone and at one end of each short

bone, e.g., metacarpal and phalanges. Maturation

occurs at the nonepiphyseal ends of short bones

also, but, at these” sites, it is difficult to divide

the process into stages that can be distinguished

radiographically.

The histological changes associated with endochondral ossification are the same, whether this

occurs in the central part of the model or in the

epiphyseal cartilage near the ends of the diaphysis. 9 The ossified area in each epiphyseal

cartilage enlarges and, within a few years, the

“cartilage is replaced completely, except for that

in contact with the end of the diaphysis and on

the articular surface (figure 1-F). During this

phase, the replacement of cartilage by bone is

more rapid than the grow~h of cartilage.

At first, an epiphyseal ossification center

enlarges rapidly in all directions; later it enlarges more rapidly in some directions than

others. 9’20 Consequently, the shape of the center

gradually resembles that of the cartilaginous

end of the bone.21 These shape changes are very

important in assessment. The epiphyseal ossification center enlarges by the apposition of bone

to each aspect except where the center is in contact with the cartilage of the epiphyseal zone?2’23

A transverse layer of cartilage remains between the diaphysis and the ossified epiphysis

after bone has replaced most of the epiphyseal

cartilage, This transverse layer, together with

the end of the diaphysis, is important not only in

diaphyseal elongation but in the radiographic assessment of maturity. In this zone, chondrocytes

hypertrophy and vacuolize, and the cartilage calcifies pre~aratoiy to its replacement by bone.

These chwlges are the same as those that occurred earlier during endochondral ossification

in other parts of the cartilage model. These

changes are more regular in the epiphyseal

layer where there is a columnar arrangement of

chondrocytes and a corresponding arrangement of

matrix and blood vessels.

The aspect of the epiphyseal ossification

center in contact with the epiphyseal layer increases in cross-sectional area more rapidly

than either the end of the diaphysis or the epiphyseal zone cartilage. It has been claimed that

a collar of periosteal bone, extending from the

margin of the diaphysis around the edge of the

epiphyseal zone, limits the increase in the crosssectional area of this zone. 24*25 The opposite

view ‘has been st~ted also: that this collar is necessary for the increase in the area of the zone?6

The evidence available indicates that this collar

is neither a mechanical barrier to the migration

of new chondrocytes nor a site of their formation. 27 Rather, the increase in th. cross- seetional area of the epiphyseal zone is due to the

formation of new chondrocytes in the proliferative layer of the perichondrium and their subsequent migration into the zone. 27-30 The increased cross-sectional area of this zone leads

to increases in the cross-sectional areas of the

diaphyseal aspect of the epiphysis and of the end

of the diaphysis (flaring). These changes are visible radiographically and are very important in

asses sment.31

After an epiphyseal zone is present, the adjacent surfaces of the epiphyseal ossification

center and of the diaphysis gradually become reciprocal in contour. The associated radiographic

changes are used to assess skeletal maturity.

Later, the diaphyseal aspect of the epiphyseal

center is covered by a thin densely radio-opaque

layer of bone which is used as a maturity indicator. As adult levels of maturity are approached,

a thin undulating layer of bone covers the end of

the diaphysis and separates it from the calcified

cartilage of the epiphyseal zone. 32 This layer of

bone and the adjoining calcified cartilage together

cause a dense radio-opaque line that is used in

assessment.

The changes as the end of the diaphysis

(metaphysics) is progressively transformed and

relocated to a relatively more central position33

cannot be graded radiographically. However, the

ridges that develop at the limits of some muscular attachments cause radio-opaque lines that

are used in assessment, e.g., at the distal portion

of the ulnar diaphysis.5

A
mm F wt. &!w A F TII. dmwtrnn dim ma.m!c. AZ J O,UIM 537994.1067

Figure 2. A diagram of the maturation of a carpal bone in which

total size has been kept constant. The approximate age scale

is: A, prenatal; B, 1-3 years; C, 4-5 years; D, 6 years; E, 10

years and F, adulthood.

“rhe final phase of the maturation of along

bone is fusion between the epiphysis and the

diaphysis. This is preceded by the cessation of

skeletal elongation and the formationof a thick

layer of calcified cartilage in the epiphyseal

zone. 34’35 This calcified cartilage is replaced

slowly by bone and, progressively, the remaining

epiphyseal zone cartilage is calcified and replaced

by bone. There is little doubt that this process is

completed first in the central part of the zone,

despite some opposite views. 36’37”Ossification

of the peripheral part of an epiphyseal zone cartilage may .t-emain incomplete for long periods

causing a groove on the surface of a bone that

may be visible radiographically. After bony

fusion between the epiphysis and diaphysis is

complete, the articular cartilage is the sole remlnant of the cartilaginous model. The bone has

now attained adult tni~turity (figure 1-G).

Subsequent to epiphyseo-diaphy seal fusion,

the layer of bone that joined the adjacent surfaces

of the epiphyseal center and the diaphysis is

resorbed. This resorption may be delayed for a

long time. When this layer persists, it is visible

radiographically.38’3 9

Many corresponding stages occur during the

maturation of the carpal bones that are in the

wrist between the forearm bones and the short

bones of the hand. A major difference is that the

carpal bones do not develop epiphyseal zones or

epiphyseal ossification centers. Each carpal bone

first develops as a condensation of embryonic

connect ive tissue. Subsequently, cavitation occurs

in this connective tissue in the region of future

joints between the carpal and neighboring bones.

After this occurs, the cartilaginous model, now

resembling the future bone in shape, articulates

with its neighbors on adjacent surfaces and is

covered by a well-defined perichondrium on other

surfaces (figure 2-A), Ossification begins in this

cartilaginous model (figure 2-B, 2-C) with the

same histological processes as those described

for endochondral ossification of long bones. 40

At first, the ossified area expands rapidly in all

directions; 9 later growth ,is more rapid in some

directions than mhers. The changes as the ossified area gradually matures and matches more

closely the shape of the adult carpal (figure 2-D,

2-E, 2-F) are used in assessment of skeletal

maturity levels of children from their radiographs.

Radiographic Changes

Studies preceding the introduction of radiography drew attention to mmy macroscopic differences between the skeletons of children and

adults. These studies were limited to postmortem

material; usually the medical history was unknown and the techniques employed (e.g., dissection, histological section) did not allow serial

studies of individuals. Knowledge of skeletal

maturation increased rapidly after radiographic

techniques became available. Only a few studies

selected from .s very large body of literature

will be mentioned. Retch 41described 13 recognizable stages in the development of the handwrist. Later, stages of carpal maturation42 and of

epiphyseo-diaphyseal fusion were described.43*44

These studies led to the elaboration of the

Todd method of assessment. 45

The radiographically visible changes used to

assess skeletal maturity are known as “maturity

indicators. ” What can be seen in radiographs are

maturity indicators, not skeletal maturity. By

definition, these indicators appear in a fixed

sequence for each bone 5*46*47 although the sequence is not fixed for an area, e.g., hand-wrist,

that includes many bones. 48-50 Each of these indicators must appear during maturation in every

child to be useful in the assessment of skeletal

maturity. 47

The radiographic assessment of skeletal

maturity depends on the presence and relative

radiodensity of areas of calcification or ossi5
fication. These differences in radiodensity, although observed in two-dimensional radiographs,

reflect three-dimensional shapes of radio-opaque

calcified or ossified areas. Parts of the surfaces

of these areas (especially the dense cortex of

bone) that are approximately parallel to the central axis of the radiographic beam cause dense

white zones on a radiograph. If these zones are

long and narrow, they arereferred teas “lines”

and are commonly called “radio- opaque lines”

because the structures causing them are relatively radio-opaque.

The changes in contour that occur during

maturation, as bones become more adult inshape

are important in the radiographic assessment

of maturity. These contour changes reflect different rates of bone apposition at various areas.

Changes in shape cannot occur witbout changes

in size. Thompson has indicated that form is determined by the rates of growth in different

directions.51 However, all the elements of size

used in the assessment of maturity concern relative size (shape) not absolute size. As emphasized by Todd, 45 the use of absolute size would

lead to the unacceptable conclusion that adults

differ in maturity because they differ in absolute

size. This would destroy one major advantage of

the present scale of maturity.

Scale of Maturity

The scale used in radiographic assessment

is based on the assumption that skeletal maturity

is absent at conception and that all individuals

reach the same level of complete maturity in

young adulthood. By this premise, each individual achieves the same amount of maturation between conception and adulthood, although there are

individual differences in rates. In practice, the

origin of the scale is the onset of epiphyseal or

carpal ossification, as observed radiographically.

Bones that develop epiphyseal ossification centers

cannot be assessed reliably before this stage!2’53

Similarly, carpal “bones” cannot be assessed

until they are visible radiographically. Some

radio-opaque epiphyseal or carpal centers probably consist of calcified cartilage rather than

bone when assessors regard them as “ossified.”

The only convincing radiographic evidence that

bone is present is the recognition of trabeculae

and these may not be visible for a considerable

period after the center becomes radio-opaque.

The end point of the skeletal maturity scale is

the completion of epiphyseo-diaphyseal fusion

in bones that have epiphyses and the attainment

of final adult shape in carpal bones.

There are two scales that can be used to

make bone-specific skeletal age assessments of

the hand-wrist. The Tanner-Whitehouse method54

is always used in a bone-specific way and the

Greulich-Pyle scale can be used to”obtain either

overall or bone-specific skeletal ages. These

scales for individual bones are not divided into

intervals known to be equivalent to each other.

These ordinal scales do not measwe skeletal

maturity but allow a maturation level to be assigned to a radiograph relative to standards. Like

other ordinal scales, they allow rank ordering,

in this case, of the degree of maturity. The standards that are used represent the central tendencies

of skeletal maturity level in healthy children

grouped by age and sex. The levels (assessments)

are recorded in years or months of skeletal age.

Typically, girls achieve adult levels of skeletal

maturity at younger chronological ages than do

boys. Consequently, girls mature more than boys

during a “skeletal age year.” Furthermore, individual bones differ in the average chronological

ages at which they reach adttlt maturity levels.

Hence the percentage of adult maturity achieved

per skeletal age year must differ among bones.

It is known that a boy with a skeletal age of

2 years is more mature than a boy with a skeletal

age of 1 year. However, one cannot conclude that

he is twice as mature because of the lack of skeletal maturity units that are equivalent to each

other. Nevertheless, because all boys mature

until they reach the same adult level of maturity,

it follows that all boys at the same skeletal maturity level have achieved the same percentage

of adult maturity, although the actual percentage

of skeletal maturity is unknown. This is the major

advantage of the ordinal scale of skeletal maturity

that is used. By contrast, many physical characteristics of children, e.g., stature, are recorded

using a cardinal scale. With such scales, ratios

between measures can be calculated, e.g., a boy

weighing 70 kilograms is twice as heavy as a

boy weighing 35 kilograms. This advantage of

the cardinal scale is offset to some extent by the

6
fact that adults differ in weight and, therefore,

one should not infer that two boys, each weighing

60 kilograms, have each achieved the same

percentage of their adult weights. The limitations

of some scales have not always been recognized.

For example, some dental maturity scales are

based on the assumption that incompletely developed roots of teeth can be classified as onefourth complete, one-third complete, etc. 55’56

These methods imply that root lengths are the

same in all adults.

The scale used to assess the Cycle II radiographs is presented in the radiographic standard

of reference of Pyle et al., 6 which is referred

to in this report as the HES Standard. This new

scale was derived principally from the Greulich -

Pyle Atlas, 5 which contains reproductions of

ordered sets of radiographs for each sex. Each

of these radiographic standards bis accompanied

by skeletal age equivalents in months or years

for each bone.

THE HEALTH EXAMINATION

SURVEY STANDARD

As stated in the Introduction, a new radiographic standard for the assessment of skeletal

mi~turity of the hand-wrist was developed by Drs.

Greulich and Pyle in collaboration with Dr. Waterhouse at the request of and for specific use in

the U.S. National Health Examination Survey. The

major difference from the Greulich-P yle Atlas

is that the HES Standard contains a single series

of plates by which the two sexes are assessed

and compared. The rationale is based on the

premises that the process of growth implies

maturation, that there are marked individual

differences in the timing and velocity of maturation but not the sequence, and that the rate

of skeletal maturation in the hand-wrist is an

acceptable indicator, for the purposes of this

survey, of the rate of overall skeletal maturation

of a child. This standard further assumes that

selected transitional, ossifying features and arcicular facets in the cortices of growing bones are

maturity indicators identifiable on all children’s

radiographs, and that they are generally the same

%Iwmet.hodbywhichthe standardmii.graphswe.. sel.ctcd is describedby Gttxdich and Pyle5 and Pyle et d.6

for both sexes and all races, and that the chronological intervals between these transitional features of growing bones are not uniform. The process of maturation occurs, on the average, more

slowly in males than in females. Consequently,

when a single series of standards is used for

both sexes, two sets of chronological age equivalems are required.

The HES Standard for the hand-wrist has

been based on and in part abstracted from the

1959 Greulich and Pyle Radiographic Atlas. 5

The Atlas was in turn based principally on the

research radiographs and other data from the

Brush Foundation Study of Human Growth and Development of Cleveland, Oaio, which was organized in 1929 and directed for the first 10 years

by Dr. T. Wingate Todd. The Greulich and Pyle

Atlas was designed for direct skeletal age readings from 3 months to 18 years with radiographic

standards at intervals of 3 to approximately 12

months depending upon the modal rate of maturation in the period. The Atlas contains one series

of standards (modal radiographs) and skeletal

ages for males and another series of standards

and skeletal ages for females.

Most of the radiographic plates used in preparing the HES Standard were selected from the

male hand-wrist series, pages 80-123 in the

Greulich-Pyle Atlas. 5 With appropriate modification and supplementation, the y provided a series

of typically occurring discernible features of

developing hand-wrist bones-a series spaced at

irregular intervals from 3.8 months to 228 months

of skeletal age. These features were related, as

accurately as possible, to the chronological age

level at which they typically appeared in the modal .

position for the Cleveland boys and girls who were

enrolled in the Brush study. To assign female

skeletal age equivalents to these male standards,

three sets of hand-wrist radiographs of girls

were assessed using the survey standard of reference for the male hand and wrist.

Although each plate in the published HES

Standard shows the skeletal age equivalents for

both males and females, those who assessed the

survey radiographs were not told the sex (or

chronological age) of any child whose radiograph

was being assessed. The skeletal ages assigned

were based on the male equivalents accompanying

each standard plate. In this report, the skeletal

7
age data for girls are shown both as directly

as$essed on the basis of the male. standards and

after conversion by computer to the corresponding skeletal ages for girls based on equivalents

in the manual. It was intended by means of this

national survey of children, and the subsequent

one of youth (12-17 years), to obtain more precise

estimates of the comparative levels of skeletal

maturation between the two sexes. In earlier

studies of. sex-associated differences in skeletal

maturity levels, the sex of the children was

known by the assessors and this could have influenced the subjective judgments that were made.

METHODS

At each of the 40 selected locations throughout the United States, the children were provided

with transportation to and from centrally located

mobile centers specially designed for an examination that lasted about 2?4hours. Six children

were examined in the morning and six in the afternoon. When each child entered the mobile center,

his oral temperature was taken and a screening

for acute illness was made; if illness was detected,

he w sent home and reexamined later. Each

examinee next dressed in shorts, cotton s%veat

socks, and a light sleeveless shirt and proceeded

to a designated but different station for the examination; the sequence of elements in the examination

differed for each child so that the six could be

examined simultaneo~sly during the half day. The

same examiners—physician, dentist, psychologist, and specially trained technicians—conducted

their parts of the examination in essentially the

same manner for each child. The time of each

examination was recorded, but there is no reason

to believe that diurnal or sequence effects would

be present in the composition or quality of the

radiographic data. The number of radiographs

assessed is given by year of age in appendix

table I.

Field Radiography

Each child was scheduled to have a 10” x 12”

radiograph of the right hand and wrist taken at a

tube-film distance of 36 inches. However, due to

the shortage of radiographic film of this size

during part of the survey, 600 radiographs were

taken (at the same distance) using either larger

or smaller films. The positiolling for radiography

was otherwise in accordance with the specifications in the Greulich-Pyle Atlas. 5 Because the

films were developed immediately in the field,

technically inadequate ones could be repeated.

Thus each child’s record contains a single radiograph showing the dorso-palmar view of his entire hand-wrist with its full complement of ossifying parts, at his examination age. Ninety-eight

percent of the radiographs were technically satisfactory for this report (94 percent of the total

sample).

The decision to radiograph the right handwrist rather than the left, which is the more frequent anthropometric practice, was made on the

advice of anthropologist consultants who were

interested also in the use of related measurement

data for equipment design in which right-side

measurements were preferred. The GreulichPyle Atlas was designed for the assessment of

the left hand-wrist. When the Atlas standards

were reproduced in the HES Standard, they were

reversed photographically so that they could be

used im right-side assessmams. Previous reported research on lateral differences in the

skeletal maturity of the hand-wrist, either for

the area as a whole or bone by bone, has shown

that these are too small to be of practical importance. 79

Training of Assessors

The assessment of skeletal age from the handwrist radiographs of children 6-11 years of age

in the Health Examination Survey of 1963-65

was made by six msdical students at Case Western Reserve University, including one who was

an instructor specializing in anatomy, This work

was done under contract, with Dr. C. Wesley

Dupertius as Project Director, for the National

Center for Health Statistics. Prior to the training

of these medical students, under the direction

and meticulous supervision of Dr. Pyle, each assessor was required to demonstrate his familiarity with the series of maturity indicators of

individual bones in the hand-wrist as described

on pages 185-228 of the Greulich and Pyle Atlas.5

The practice procedures used in training

were based on 30 contact-size prints of the hand-
wrist radiographs used with the 1959 edition of

the Radiographic Atlas andavalidating test based

on another set ofprints ofhand-wrist radiographs

with which the preliminary version of the HES

Standard (showing only the male standard skeletal

ages for each plate and each bone) was used.

During the practice, each assessor first

arranged 30 prinw in ascending skeletal maturity

order. The bone- specific skeletal ages for each

print were assessed according to the male standards in the Greulich and Pyle Atlas5 and the corresponding skeletal age of the hand-wrist for each

print was determined by averaging these skeletal

ages. Next, the 30 prints were rearranged according to those hand-wrist skeletal ages and the new

array was assessed according to the female

stzznckwds in the Greulich and Pyle Atlas. Then,

the first set of bone-specific skeletal ages, based

on the male standards, were covered and a second

set of bone-specific skeletal age assessments

was obtained using the male standards for the

second time. The first and second sets oi assessments were compared, and the assessor decidzd

which he considered the better final rating for

each print. These ratings were reviewed to determine whether the assessor needed additional

practice and training before proceeding to the

next phase. When the project director considered

that the assessments were sufficiently reliable,

the assessor was given the validating test in which

his assessments and the extent of variability in

his independent reassessments were compared

with those of Dr. Pyle. W!len the ratings and reliability for the new assessor were in good agreement with those by Dr. Pyle--the majority of

differences within 4 months—the new assessor

started his assessment of the survey radiographs.

Reported evidence 53 suggests that, at the end

of this training procedure, the interobserver and

intraobserver differences in skeletal maturity

ratings should have been similar to those for experienced assessors.

Assessment Procedure

All survey radiographs were assessed by

comparison with prints of the series of standards

for the male hand-wrist which appear on pages 80

through 123 of the Greulich-Pyle Atlas,5 as modified for inclusion in the HES Standard but showing

the skeletal age equivalents for males only. The

readers did not have access to the chronological

age, the sex, or any other information about the

child. When it appeared appropriate, the assessors

interpolated between the” standards to monthly

intervals.

As a quality control measure and to permiz

determination of the level of reliability of the

assessments throughout this study, independent

replicate assessments were obtained on approximately one out of each 11 radiographs. One randomly selected radiograph from each 23 was

rated independently by another assessor for a

measure of interobserver variability and one

randomly selected radiograph among each 20 was

rated independently a second time by the same

reader to give a measure of intraobserver variability. At the second assessment, there was no

indication to :he assessor that it was a reassessment and there was sufficient time lapse between

the two assessments that there was little likelihood of recall. Information on the degree of

reliability of these assessments is contained in

append& H.

In skeletal age assessments using reference

standards, there are limits to the range of skeletal ages that can be applied to each bone. For

example, as shown in table A, the trapezoid is

not visible until plate 12 of the HES Standard, 6

where the skeletal age (hand-wrist)is the equivalent of 72 months and the trapezoid shadow

measures about 4.5 x 4.0 mm.; the trapezoid

would be smaller than this when first radioopaque. Thus it is reasonable to assign an age

slightly less than 72 months to some radiographs.

However, the assigned skeletal age must exceed

60 months because at that level (plate 11) the

trapezoid is not radio-opaque. Lower limits for

these assessments were arbitrarily set for each

bone that was midway in skeletal age between the

last standard in which the particular bone was

not radio-opaque and the P.rst in which it was

radio-opaque. Three exceptions were made: for

the pisiform and the adductor and flexor sesamoids, minimum ages for 2 months above the

last non-radio-opaque plate were aHowed. These

exceptions were made because the limits were

set aJtW the assessments had been made and,

for many radiographs, the assigned ages for

9
Table A. Minimum and maxi-mumacceptable

sk~letalages in months using the HES

male standards:Health Examinaei,onSurvey, 1963-65

Hand-wristbone

Radius--------------------

Ulna----------------------

Capitate------------------

Hamate--------------------

Triquetral----------------

Lunate--------------------

Scaphoid-----.------------

Trapezium-----------------

Trapezoid-----------------

Metacarpal I--------------

Metacarpal II-------------

Metacarpal III------------

Metacarpal IV-------------

MetacarpalV--------------

Proximal phalanx I--------

Proximal phalanx II-V-----

Middle

Middle

Distal

Distal

Distal

Distal

phlanx II-IV-------

phalanx V----------

phalanx I----------

phalanx 11, V------

phalanx III--------

phalanx IV---------

Pisiform------------------

Adduccor sesamoid---------

Flexor sesamoid-----------

tiinirnuma

Maximumb

Skeletalage

in months

15

70

---

---

17

35

!!!

68

25

17

16

;;

;2

23

39

15

%

32

110

146

158

228

215

197

197

197

197

197

197

197

191

215

209

209

215

215

209

209

209

191

191

191

191

197

197

197

aMinimumage (accordingto standard)of

radio-opacityof epiphysisor carpal.

bone month below “adult” age.

these threeboneswere slightlylowerthanthe

“midway”limits.

Therearelimls alsoattheupperendofthe

ra.l,ge,when bonesbecome adult.O.dythedesignation“adult,”and nota skeletalageinmonths,

can be assignedto a bone inwhichmaturation

iscomplete.The medianagesfromcheHESStandard,atwhichthisoccursin boys,were usedto

calculateskeletalages in months foreachbone

beyondwhich onlythedesignation’’adult”canbe

applied.The maximum valueswere assigned1

month belowthe“addt” skeletalage as shown

in tableA. In the assessmentsof thesurvey

radiographs,bone-specificmale skeletalages

were assignedtobothboysandgirls;theassessordidnotknow thesexofthechild.

As expected,withinchronologicalage groups,

theskeletalagesassignedtothegirlsweremore

advancedthanthoseassignedto theboys.This

occurs because,althoughboys and girlspass

throughthesame skeletalmaturitystages,girls

tendto mature more rapidlythanboys.Thefemale equivalentskeletalages,bone by bone,

correspondingto the male skeletalages were

determinedduringthe preparationof theHES

Standardbutwere notusedinassessmentofthe

surveyradiograpils. The method bywhichthese

female equivalentskeletalages were obtained

is describedindetailinPyleetal.6 Theseafges

were estimatedusingthreesetsofserialradiographsof normalUnitedStatesgirls.The modal

radiograph(inmaturity)foreach chronological

age groupin each setwas assessedagainsthe

female standardsin theGreulich–PyleAtlas5

and againsttheHES Standard(male).Thesesequentialfemale equivalentskeletalages were

thensmoothed.

The skeletalage dataforgirlsinthisreportare givenbothin termsofthemale standards as originallyassessedand intermsofthe

femaleequivalentskeletalages.The laterconversionwas done,boneby bone,usingtheequivalencydatain theHES Standardwithinterpolationbetweenthepublishedvaluestomonthlyintervals.The skeletalage(hand-wrist)valuesfor

boys and girlsinthisreportwere determined

by computerfrom theoriginalboae-specificassessmmts by averagingtheages assignedeach

hand-wristboneforthechild.

FINDINGS

Skeletal Age (Hand-Wrist)

The mean skeletalage (hand-wrist)ofboys

in theUnitedStatesincreasesconsistently with

chronologicalage from 6.3years (75.5months)

for those6 yearsof age at theirIastbirthday

(meanchronologicalge,6.5yearsor 78months)

to10.4years(124.2months)atchronologicalge

11 years (mean, 11.5years or 138 months)

(table1).

10
oF-

:

u ‘1

i

............

......

g ....

-5 -

....

d %.

....

;

..,.

...

g ..,6

% .,Q .

...O

..6.

Y ...+

$ ..,.

t ““””............

ti

% -15 I I I I [ I

6 7 8 9 10 11 1:

CHRONOLOGICAL AGE IN YEARS

Figure 3, Mean difference in months betweenskeletal age (handwrist) and chronological age of boys, by chronological age in

years: United States, 1963-65.

The reader is reminded that the findings

shown in this report are national estimates derived from data of the Health Examination Survey

collected in 1963-65. The hand-wrist radiograph

assessments of skeletal age were made using the

FIRS Standard, 6 which is based on the GreulichPyle Radiographic Atlas, 5 as previwsly described. On the basis of these assessments, the

skeletal age (hand-wrist) of boys does not prowess as fast as their chronological age does, .<

from a mean difference of 2.5 months at chronological age 6 years to nearly 14 months at chronological age 11 years (figure 3). The mean

differences between chronological and skeletal

ages of boys are statistically significant at the

5-percent probability level (i.e., exceed the

Qs-percent confidence limits fo: these estimates)

or less throughout the age range in the study.

Among girls, when assessment is made

against the HES Standard for males by readers

not knowing the sex of the child, the mean skeletal age (hand-wrist) increases consistently from

7.5 years (90.0 months) at 6 years of chronological age (mean, 6.5 years or 78 months) to

13.1 years (156.5 months) at chronological age

11 years (mean, 11.5 years or 138 months). The

skeletal age ratings against the male standard

consistently exceeded the chronological age of

American girls by differences ranging on the

average from 12 months at age 6 years to 18.5

m,.,nths at age 11 years (figure 4). Althoagh they

show no consistent linear trend with chronological age, the differences tend to be smaller at

zo~

..- /

u! /

2

...

~-l 15 -

...

~<$%

...

Ou ...””

ZCJ ...

50 . . . . . . . . . . . . . .

,,.””

g$ ,0 -

.. ....

...””

~: ... .. .. . . . . .

.....

. . . . . . . . . ...

;:

~:

z:

z<$~ 5 -

z~

g

OL I I I I I I

6 7 8 9 10 11 12

CHRONOLOGICAL AGE IN YEARS

Figure 4. Mean difference in months between skeletal age (handwrist) on the male standard and chronological age of girls, by

chronological age in years: United Statesr 1963-65.

chronological ages 8 and 9 years than earlier or

later.

In terms of the fem~.le equivalent skeletal

ages corresponding to and derived from the male

skeletal ages, as described in the “Methods” sect ion, the mean skeletal age (hand-wrist) of

American girls also increases consistently with

chronological age from 6.4 years (77.0 months)

among those 6 years of age at their last birthday

to 10.7 years (128.2 months) at chronological age

11 years. As in the case of boys, the skeletal age

of girls on the average lags consistently behind

their chronological age (figure 5). The differences

6 7 s 9 10 lT 12

CHRONOLOGICAL AGE IN YEARS

Figure 5. Mean difference in months between skeletal age (handwrist) and chronological age of boys and girls (female equivalent values of skeletal age used for girls), by chronological age

in years: United States, 1963-65.

11
across chronological age are at a minimum of

1-2 months among 6- and 7-year-old girls, increase to about 6 months at ages 8 and 9 years,

and reach a mi~xirnum between 9 and 10 months

at ages 10 and 11 years.

Am,mg both boys and girls, the marked

tendency for skeletal age to be increasingly

lower than chronological age as chronological

age increases is clearly demonstrated in figures

3 and 5, where the findings are expressed as the

difference between the respective means for

skeletal age (female equivalent values for girls)

and chronological age.

Coml)arison of skeletal ages for boys with

those for girls (using the female equivalent values

for the latter) shows close agreement among those

8 years of age (at their last birthday), where the

mean skeletal age of boys exceeds that for girls

by less than 1 month (figure 5). Among other

younger children—at 6, 7, and 9 years—the mean

skeletal ages for girls are 1-2 months in advance

of those for keys, while among the oldest children— 10 and 11 years—girls are substantially

mo.-e advanced than boys by mean values of 3-4

mont~ls. These latter differences are statistically

significant at the 5-percent probability level.

The mean skeletal age (hand-wrist) at

6-month intervals of chronological age shows a

consistent pattern of increase with chronological

age for both boys and girls similar to that at a,mual

chronological age intervals (table 1). However,

the actual rate of increase in skeletal age over

successive 6-month periods of chronological age

varies among both boys and girls but generally

te,lds to be somewhat slower among bojw. Among

boys the mean increase in skeletal age between

the first and the last half of chronological age

11 years is slightly greater than for yo~nger boys

and girls, while for girls of chronological age

11 years the mean increase in skeletal age between the first and last half of the year is less

than for younger girls. Only among the oldest

children in this study (chronological age 11) is

the difference in the mean increase in skeletal

age between boys and girls large enough to be

statistically significant at the 5-percent probability leveI.

At single-mmth intervals of chronological

age, the mean skeletal ages show a similar but

less consistent pattern (table 2), primarily because the sample is too small to provide reliable

mean estimates within these brief intervals. However, the high level of association between skeletal

age (hand-wrist) and chronological age is readily

apparent. The rectilinear product-moment correlation coefficient between the two measures of

age is slightly but not significantly (statistically) greater among girls than boys-+.85 and

+.82, respectively.

The extent of variation in skeletal ages

among boys and girls, as rnmsured by the standard deviations, does not increase consistently

with the mean values. Among boys, the standard

deviations in skeletal age ranged from a low of

9.9 months for those of chronological age 10

years (at their last birthday) to 12.5 months at

chronological age 11 years; among girls these

values range from 1.0.1 months of skeletal age

(female equivalent values) at chronological age

7 years to 13.8 months at chronological age 10

years (table 1). TrLe variability in skeletal age

among girls, but not boys, was slightly greater

among older (9- 11 years of chronological age)

than younger children (6-8 years). The relative

variability in relation to the mean, as measured

by the coefficient of variation (100 SX/ x ) is

greatest among the youngest boys and girls (14.8

and 13.6, respectively, at chronological age 6

years as shown in figure 6). Among boys, but

not girls, the coefficient decreases consistently

with chronological age from 14.8 at age 6 years

to 8.7 at chronological age 10 years. Boys tended

to show slightly greater relative variability in

‘6 7 8 9 10 11 12

cHRONOLOGICAL AGE IN YEARS

Figure 6. Relativa variability in skeletal age (hand-wrist) for

boys and girls, by chronological age in years: United States,

1963-65.

12
skeletal age than girls at four of the six chronological years of age, the two exceptions being

at ages 9 and 10 years.

The distribution of skeletal age (hand-wrist)

for boys and girls in the United States is similar

and essentially normal at each chronological

year of age (tables 1 and 3). The approximate chisquare test of goodness of fit to the normal curve

indicates only chance differences that are not

significant at the 5-percent probability level

(X:4 =0,21-3.5s, for the individual years Of a&

and for each p> 99). Consequently, the mean and

median skeletal age values are generally in close

agreemfint. Only in four of the 12 age-sex groups

of boys and girls do the mean and median skeletal

ages differ by as much as 2-3 months. At chronological age 11 years for boys and 9 for girls

(femille equivalent values) the median skeletal

ages are both lower than the mean by 2.6 months;

while at chronological age 7 years for girls and

9 years for boys the median values are greater

than the means by 2.0 and 1.8 months, respectively.

The percentage distributions of skeletal age

(hand-wrist) among children within each chronological yearly and 6-mmth age interval are

shown in tables 3 and 4. The interquartile range

(P75 - P25) or the central half of the distribution

of the differences between chronological and

skeletal ages, as shown in figure 7, for boys is

lowest at age 10 years (range of 12 months),

while differences at the other ages vary between

15 and 18 months. Among girls (female equivalent

values) this measure of variability ranges from

a minimum of 11 months at chronological ages

8 and 11 years to a high of 19 months at age 6

years. The 90-percent range (P95- P5 ) in the

distribution of differences between chronological

and skeletal age shows less variability with respect to chronological age. For boys this 90-percent range is at a rn:nimlm (35 months) at chronological ages 9 and 10 years and for girls (femi~le

equivalent values of skeletal age) at chronological

ages 8 and 11 years, while it reaches a maximum

of 42 months for boys at chronological age 11

and of 40 months for girls at chronological age

6 years.

Comparison with previous findings in the

United States. —Comparison with findings from

previous studies has been restricted to those including at least 25 boys or 25 girls at each age

interval. In most of these investigations, radiographs were taken of the left hand-wrist, but the

possible small lateral differences in skeletal

20

10 [

BOYS

PERCENTILE

.,......

...” ,.

. . . . . .

. . .

. . . . ~bth

“... ..””

. .. .. . . .

...””

““%. . . . . . . . ...”

. . . .../.. -------- -=

‘%

K

%

~%%

--------------- >

+.- --- ~5th

-<%

--+ ‘%

-+ ‘.

-...

--- -. ~th

—-

\

‘L

>. 25th

‘%--~

‘%-~s’h

20-

10

0 -

-10

.20 —

-30

GIRLS . FEMALE EQUIVALENT VALUES

....

.....%.

...

...... .......................

....

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-.. + ................ @h

--.

‘-

-...

.------+% -------

-.

‘. - #

-...

-+. ~- ~oth

__44\ ----- =--

\\

-----25’”

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-—-~-

-—-

- 5ti

L_l_uJJ

6 7 8 9 10 11 12

.oL_u_J—— 6 7 8 9 10 11 12

CHRONOLOGICAL AGE IN YEARS cHRONOLOGICAL AGE IN YEARS

Figure7. Selected percentiles in the distribution of the differences between skeletal (hand-wrist) and chronological ages for boys and

girls (female equivalent values of skeletal age used for girls), by chronological age in years: United States, 1963-65.

13
maturity have been disregarded in this review.

Means and standard deviations for skeletal

age have been reported within chronological

age groups by Simmons, 57 Greulich and Pyle, 5

Johnston,58and Fry~9Maresh6 ‘reported medians.

To facilitate comparisons, the data reported by various investigators have been adjusted to a common Greulich-Pyle baseline. To

achieve this adjustment for those reports, the

standard modal plates of Flory61 and Todd45

have been assessed using the Greulich–Pyle

Atlas5 to assign bone-specific ages, interpolatingwhen this appeared desirable. Thematurity

levels assigned to the Floryand Todd plates resemble medians ra:her than means.

The Greulich- Pyle standards were selected

from radiographs of white children of upper

socioeconomic status living in Cleveland. These

children were born between 1917 and 1942 and

were radiographer close to their birthdays and

half birthdays. The method by which these standard plates were selected from the 100 radiographs

available for each sex at each age is described

in detail in the Atlas of Greulich and Pyle.5

Mean level. —Howard 62 published standards

selected from radiographs of Atlanta public

school children born between 1917 and 1922.

These standards were selected from samples of

50 radiographs for each annual interval in each

sex. Their maturity levels are about 2 years

below those of the Greulich- Pyle standards.

The data have not been included in figures 8a and

8b because neither ethnic origin nor socioeconomic status of the sample was reported. Furthermore, the sample was too small for a reliable

selection of standards, considering that these

radiographs were taken at random chronological

ages.

A mixed longitudinal study of white Chicago

children of above average socioeconomic status

born between 1911 and 1923 was reported by

Flory. 6I Radiographs taken within 2 weeks of

a birthday were available for 100 children of

each sex at each age except 6 and 7 years, when

at least 80 radiographs were available. The plates

selected by Flory as best representing the central

tendencies in his groups are about 1 skeletal age

year below the corresponding Greulich-Pyle

standards for each sex. This difference tends to

increase with age for the boys and to decrease

for the girls (figures 8a and 8b).

Simm :)ns 57 reported mixed longitudinal data

from Cleveland children of above average socioeconomic status who were born between 1917 and

1942 and examined at or near their birthdays.

The number of radiographs assessed for each

1.0

I

--- Flwy [1936)

~

.. . . . . . g~mms (1’344)

n-- T~d (1937]

$

~

w 0.5

2

g

........

...........

/...

o

.... ......

Cj h

............ ...

/.

0 ..- /\ /’,

z

....

g /\ /

\“O”\ //

& -0.5 \ /’ \

---- \,/ \.

% ‘x,

Y

2

~

‘x

-1.0 ‘.

5

---------------------

Y

In

-1.51 ( ! 1 1 1

6 7 8 9 10 11

CHRONOLOGICAL AGE IN YEARS

Figure 8a. Differences between skeletal and chronological ages

--- Flory (1936)

.. . . . . Simmons (1944)

--- Todd [1937)

.........- ...............

.........

....... ......

...... .

/--.,~ /.” /

/ ~~---0

...”. ~---

/4 ,

*e

/

------ /’ -.. /

/’ ------ #

/

,/’

8 7 8 9 10 11

CHRONOLOGICAL AGE IN YEARS

Figure 8b. Differences between skeletal and chronological ages

of girls (female equivalent values for former) by chronological

of boys by chronological age in years in studies of Fl&y

(1936), Simmons (1944), and Todd (1937).

age- in years in studies of Flory(1936), Simmons (1944)~and

Todd (1 937).

14
year of age varied from 1.54 t0206in each sex.

After adjustment to compensate for the use of

the Todd Atlas, all the mean skeletal ages reported by Sim,mons are within 0.5 year (skeletal

age) of the Greulich-P yle standards. This close

correspondence is not surprising because the

radiographs used by Simmons formed part of

the sample used by Greulich and Pyle. In each

sex, there is a tendency for the means of Simmons

to be slightly higher than those of Greulich and

Pyle at 7-10 years for boys aod 8-10 years for

girls but not at 6 and 11 years for either sex.

Todd’s Atlas 45 was based on radiographs of

Cleveland children of all socioeconomi~ levels

who were born between 1920 and 1930 and examined serially near each birthday or half birthday. The standard plates were selected from

Samples of 35-94 children of each sex for each

6 months of age. The median levels of the Todd

Atlas are about 0.5 year (skeletal age) lower

than the Greulich-P yle standards at most ages

in both boys and girls (figures 8a and 8b). Expectedly, the maturity levels of Todd 45 are lower

than those of Simmons. 57 Although there was

some overlap between the samples of radiographs used by these two investigators, Simmons

used only those of children who were of high

socioeconomic status; Todd used radiographs of

children from all socioeconomic levels.

Mixed longitudinal data from the Harvard

Growth Study were reported by Greulich and

Pyle. 5 These radiographs were of white middle

class Boston children who were born between

1930 and 1939 and examined near each birthday.

The sample size varied from 63 to 67 at each

age in each sex. All the mean skele[al ages are

within 0.3 year of the corresponding Greulich -

Pyle standards.

Johnston 58 reported mixed longitudinal data

f.-om middle and upper middle class Philadelphia

white children who were born between 1937 and

19S5. The sample size varied from 23 to 51 for

each annual interval in each sex. The examinations

were made at random chronological ages. Consequently, the data relating to, for example, “9

years chronological age” were derived from

children ranging in age from 8.5 to 9.49 years.

The mean skeletal ages for the boys gradually

advanced, with chronological age, relative to the

Greulich-Pyle standards, until the mean was

advanced 0.65 year at the age of 11 years. The

means for the girls were within 0.3 year of the

Greulich-Pyle standards at all ages.

Skeletal age data from middle class white

children (including many twins) in Nebraska born

between 1950 and 1960 and exam;ned cross-sectionally at random ages have been reported by

Fry. 59 The sample for each annual interval included 25 boys and 25 girls. The mean skeletal

ages for the boys were below the Greulich-P yle

standards by amounts that exceeded 1 year

(skeletal age) at 6 and 7 years. These differences

for the boys decreased with increasing chronological age. The mean skeletal ages for the

girls also were below the Greulich-Pyle standards at most ages by about 0.5 year (figures 9a

and 9b).

Mixed longitudinal data from middle class

white children living in Denver were obtained

from radiographs taken close to birthdays and

half birthdays. These children were born between

1915 and 1964, but most of the radiographs were

taken after 1947. The sample size varied from

39 to 57 for each 6-month age interval in each

sex. 60 The median skeletal ages for boys and

girls were about 0.6 year below the GreulichPyle standards during the age range 6-11 years.

In general the data reported by those who

have applied the Greulich-Pyle Atlas 5358-60 indicate a trend to lesser retardation of skeletal

age with increasing chronological age in boys

(figure 9a). There are similar trends for girIs

in the data of Johnston58 and Maresh 60 (figure

9b). However, the data from the present national

survey show a definite tendency to increasing

retardation in both boys and girls.

It is of interest to consider these reported

means in relation to possible secular changes

in skeletal maturity levels. As far as can be

determined, all the samples considered in this

review were similar in ethnic origin, but only

those of Flory 61 and Simmons 57 were of upper

class children. The median birth dates for the

Flory sample are 13 years in advance of those

for the sample of Sim~mons. The skeletal maturity

levels reported by Flory are lower than those

reported by Simmons, indicating a possible secular trend. The approximate medial birth dates

for the samples of middle class children are:

Greulich and Pyle (Harvard data), 1935; 5Johnston,
1.o- ...... Johnston (1962)

~ --- Gwlich and Pyle (1959)

<

--- Fry (1966)

g

--- Maresh (1971)

— United States children (1963.65) . . . . .

... . . . ...+”

U 0.5 -

a

. ..’

. . . . .

-1

1: ‘Y%z

/

$ -----~

-1.51 ! 1 1 I I

6 7 8 9 10 11

CHRONOLOGICAL AGE IN YEARS

Figure 9a. Differences between skeletal and chronologicalI ages

of boys by chronological age in years, in studies of Fry (1966),

Maresh (1971), Johnston (1952), and Greulicil and Pyle

(1959) and for United States children (1963-65).

1944;58 Maresh, 1955;63 and Fry, 1955.59 Generalizing across age and sex, the mean levels

reported by Greulich and Pyle and by Johnston

tend to be higher, while those reported by Maresh

and Fry tend to be lower. This suggestion of a

reverse secular trend could be due to the effects

of altitude (unlikely), imperfect comparability between assessors, and variations in what is considered “middle class.” It is not in agreement

with the present national survey findings, which

are based on a much larger and differently selected probability sample representative of United

States children born between 1953 and 1958 who

were still alive at the time of the survey. In the

national survey sample, the earlier born (and thus

the older at the time of the survey) tend to have

skeletal ages that are further behind their chronological ages.

Vanta bility. — Means and standard deviations

of skeletal ages, within chronological age groups,

have been reported for most of the investigations

considered here. Hence it is possible to compare

the relative variability in skeletal age in relation

to the size of the mean values for children in

these studies. Greater variability might be expected for children in the present national study

since radiographs were taken throughout the year

rather than close to birthdays or half birthdays

[Female equivalent values}

1.0

_[

--- Grwlich.P@e 119591

------ Johnston (1962]

--- Fry (l!%@

~

--- Maresh (1971)

— United States ch!ldren ! 1963 65)

!j 0.5

..

-1.0I

[ I 1 1 ,

6 7 8 9 10 11

CHRONOLOGICAL AGE IN YEARS

Figure 9b. Differences between skeletal and chronological ages

of girls, female equivalent values for the former, by chronological age in years in studies of Fry (1966), Maresh (1971),

Johnston (1952), and Greulich and Pyle (1959) and for

United States children (1963-65).

as was done in most of the previous available

studies. This factor could be responsible for the

relatively greater variability at some of the

chronological ages among boys and girls studied

by Fry.59

The relative variability y in skeletal ages reported by Simmons 57 among boys 6-10 years of

age and by Greulich and Pyle 5 among girls 6-9

years tend to be smaller than that for the corresponding age- sex group reported by others and

is smaller than that for the children in the present

national survey, when the latter are grouped into

annual age intervals. After consideration of these

reports, no clear picture emwges with regard

to possible sex-associated differences in the

variability of skeletal age. The relative variability in findings reported by Simmons 57 and

Johnston 5a tended to be slightly larger for girls

than for boys; an opposite and more marked tendency is present in the data of Flory G1 except at

8 years, Greulich and Pyle s through 10 years,

and Fry 59 at 8-11 years. The corresponding sex

differences in variability were small and inconsistent in direction in the national estimates provided by the HES data (table B).

l%e size of the probability sample in the

national survey was larger than in the other reported studies; furthermore, only such a national

survey can provide reliable estimates for the

United States population.

16
Table B. Relative variability in skeletal ages among boys and girls within chronological age groups from selected studies

Sex and age

Boys

6 years----------------------

7 years----------------------

8 years ----------------------

9 years----------------------

10 years---.----...=---------

11 years---------------------

Girls

6 years ----------------------

7 years ----------------------

8 years ----------------------

9 years---..=----------------

ICI years---.-----=-----------

11 years ---------------------

Flor#

Simmons, Greulich

and Pyle, Johnston, Frx5~

1936 1 194@7 19595 196258 1966

20.6

21.0

15.9

13.5

11.1

10.4

19.8

13.4

15.3

10.9

;:;

Coefficient of variation

13.3

10.7

9.6

8.2

8.1

7.7

15.5

11.8

10.6

9.8

n

13.7

12.5

11.7

10.6

9.7

8.0

12.7

10.1

::$

9.1

9.2

---

10.4

10.0

11.4

8.9

6.8

---

10.7

10.8

11.5

11.3

10.2

15.4

14.0

14.7

15.9

15.9

11.1

16.0

18.1

14.0

10.0

13.3

8.1

United

States,

1963-65

14.8

12.9

11.6

10.3

1::;

13.6

11.5

10.8

11.6

11.9

9.3

aCoefficient of variation = 100 standard deviation/mean.

Onset on Ossification fewer than 24 radio-opaquebones atchronologiIn the Health Examination Survey radiographs, the median age of onset of ossification

or thefirstobservable stage inskeletalmaturation

foreach of the 31 hand-wrist bones was issumed

to be midway between the last plate in the HES

Standard in yhichthe bone was not radio-opaque

and the first in which it was radio-opaque. As

shown in table A, slightly lower limits were

allowed for the pisiform and the adductor and

flexor sesamoids.

The mzdian number of radio-opaque handwrist bones among boys increased from just

under 26 at chronological age 6 years to 29at

chronological age 11 years. The girls were about

two bones advanced in this respect throughout

the age range in the national survey (table 5).As

previously discussed the term fadio-opaque for

the shorn bones, the radius, and theulnarefers

totheepiphysisratherthantheshaftofthebones.

The proportionofboys withfewer than24 radioopaque bones decreased rapidly from 9 percent

among those of chronological age 6 years to 3

percentat chronological age 7yea.rsandto lpercent or less among those of chronological ages

8-11 years. For girls, less than 1 percent had

cal age 6 years. This again indicates that girls

are more advanced in skeletalmaturity thanboys.

None ofthe31 hand-wrist boxes had reached

“adult” skeletal age among boys in the national

study, while among girls the proportion with at

least one or more assessed as ’’adult” increased

from 1 percent at chronological age9 to12 percent at chronological age 11 years.

Information concerning the modal ages of

onset of ossification for some of the later-forming bones available fromprevioussmallerstudies

is shown in table C. These previous studies included three types of modal ages: median ages

at onset of ossification, mean ages at onset of

ossification, and the percentage incidence ofossified centers within age intervals. The latter

data allow the calculation of modal ages. Estimates of modal age of onset of ossification from

the national survey are based on the chronological age at which 50 percent of the children were

found to have the bone radio-opaque. Tofacilitate

comparison, it has been assumed that anysystematic differences that are due to the method

of analysis between correspondingmean and

median ages and ages when thecenter;.spresent

in 50 percent of children can be disregarded.

17
Table C. Modal ages in years for onset of ossification in selected bones from various studies

MODAL AGES

Bone from

United States,

previous studies

1963-65

Boys

Dktat ulna .. .............. 6.7,61 7.1,6’3 7.1,’39 7.2,W 7.4,5 7.466

Trapuiurn ................ 5.9,69 5.9,6’ 6.1,5 6.2,a4, ‘s 6.3 w

Trapezoid ................ 6.0,68 6.1,64,6’ 6.2,6,69 6.8 ‘G

Pisiform .................... 10.5,5 11.0,64 11.2,6* 11.766

7.1

6.2

6.4

11.3

Girls I I

Pkifonn .................... 8.4,5 8.4,64 8.6,66 9.0,6’ 9.7 6a I

8.8

Adductor sesamoid .... 10.5,a4 10.7,69 10.8,5 11.0,20 11.266 10.7

NOTE: Modat ages for studies of Greulich and Pyle5 and Pyle et aL 20 have been increased by 0.5

to be more neady comparable with assessment methods used in the other studies (see pages 18 and 19).

The report of Flory6] concerning onset of

ossification was based on the sample described

earlier in relation to skeletal age. Essentially

the same sample of Boston children was studied

by Harding 64 and by Pyle et al., 20 and it has

been described in reference to the skeletal age

data of Bayley. 65 The sample of Denver children

studied by Hansman 66 has been described in

relation to the report of Maresh.60 Skeletal age

has been studied in the Brush Foundation sample

by Simmons; 57 ages at onset of ossification in

these children have been reported by Greulich

and Pyle. 5 Greulich and Pyle reported data

using both the whole Brush sample (more than

200 children of each sex) and also the subset of

100 boys and 100 girls whose radiographs had

been used to construct the Greulich and Pyle

Atlas. Because there are only slight differences

between corresponding mean ages for the two

Greulich-Pyle samples, table C contains single

references to both.

Lurie et al. 67 reported cross-sectional

data on 1,129 white children from Cincinnati

born between 1920 and 1940, approximately.

These children were examined at the Child

Guidance Home of the Jewish Hospital. While

not necessarily Jewish, they were referred because of emotional

from children with

marked nutritional

disturbances. Although data

endocrine disturbances or

deficiencies were excluded,

the normality of the remainder of the sample is

questionable. Consequently, these data have been

excluded from the present review. Baldwin et

aI. 68 reported mixed longitudinal data from

upper middIe class white children in Iowa City,

born between 1901 and 1928. The sample size

varied from 29 to 49 in each amual interval for

each sex. The mixed longitudinal data of Garn

et al. 69 were derived from-middle socioeconomic

class white children in southwestern Ohio who

were born between 1929 and 1966. The sample

size was about 180 for each sex in each 6-month

interval.

Considerable variation would be expected

between the findings from these reports because

the studies differ in many respects including

sampling and the methodology of radiography and

data analysis. Furthermore, most have reported

data relating to the age at which a center was seen

to be ossified; others 5’20 have recorded an age

for onset of ossification in each child that was

interpolated between the last radiograph in which

the center was not ossified and the first radiograph in which it was ossified, For this reason,

18
the means reported by Greulich and Pyle5 and

by Pyle et al.20 are about 0.5 year in advance

of those that would have been reported had the

more commonprocedur ebeenfollowed.

The modal ages based on reported data in

table C should be interpreted with care because

of these methodological differences. The ages

in the table relating to the studies by Greulich

and Pyle5 and Pyle et al.20 have been increased

by 0.5 year to compensate for some of these

differences. The reported modal ages at which

the distal epiphysis of the ulna ossifies in boys

differ comparatively little between these studies.

This age is earliest for the Flory sample b1 and

latest for the Hansman sample’6 with a difference of 0.7 year between these extremes. The

midal ages for the onset of ossification in the

trapezium in boys differ by 0.4 year from the

~arlie~t 69 to the latest. 6G The modal ages for

the trapezoid in boys differ by 0.8 year from the

early age reported by Baldwin et al.,b8 to that

reported by Hansman. 66

All these reports indicate that the pisiform

tends to ossify later in boys than in girls. The

reported modal ages range from 10.5 to 11.7

years for the boys and from %4 to 9,7 years for

the girls with Greulich and Pyle 5 reporting

relatively early ages for each sex and relatively

late ages being reported for boys by Hansman66

and for girls by Baldwin et al.68

It is of interest to compare modal ages across

studies (range 5.9 to 7.4 years) for the onset of

ossification in the distal ulnar epiphysis, the

trapezium, and trapezoid in boys.5’61’b4>G6’G8’G9

The methodological differences between these

studies would not be expected to causes ysternaic

differences between these modal ages. The ages

reported by Hansman ‘b are the latest ones for

each bone. ‘The associations between the modal

ages across bones are similar for the five studies

except that the age reported by Hansman 66 for

the trapezoid is later than one wouId expect from

:he ages she reported for other bones.

The modal ages reported for the adductor

sesamoid and the pisiform in boys differed by

1.7 years in the data of Greulich and Pyle 5 and

2.0 years in the data of Hsnsman, 66 indicating

satisfactory replicabilit y. However, the differences Ixxween the medal ages for the onset of

ossification of the pisiform in boys and girls range

from 1.5 years in the sample of Baldwin et al.’8

to 3.1 years in the Denver children studied by

Hansman. bG The unusually large difference in

the data on Denver children would lead one to

expect that the boys would be skeletally retarded

compared with the girls; there is no such tendency

in the data for hand-wrist skeletal ages from

essentially the same sample. GO

The corresponding modal ages of onset of

ossification in the U.S. children from lhe present

survey tended to be within the range of the findings from other studies of more Iimi:ed groups

of children in this cmntry, A review of some of

the survey radiographs indicated that they were

of unusually good quality and that even very small

areas of ossification in the cartilaginous model

of the pisiform had been recognized by the assessors.

Bone-Specific

Skeletal Ages

In the Greulich- Pyle method of assessm sm

as used in die national survey, bone-specific

skeletal ages are assigned each radio-opaque

hand-wrist bone. The skeletal age (hand-wrist)

is determined from these bone-specific ages.

Commonly within children the hand-wrist bones

differ in their levels of skeletal mi~turity. The

maans and standard deviations of the bone- specif -

ic skeletal ages for each of the 31 hand-wrist

bones of boys and girls 6-11 years of age in the

United States, as determined from the survey

male standard and for the girls also in terms

of the female equivalent values, are shown in

table 6 at 1-year chronological age intervals and

in table 7 at 6-month chronological age intervals.

Selected percentiles in the distributions of these

bone-specific skeletal ages within single years

of chronological age are shown in table 8.

As may be seen in figure 10 and table 6, there

is a “consistent increase in mean skeletaI age

with chronological age for each of the 28 bones

for which the modal age of onset of ossification

was below the age range of the study. For the

remaining’ three-the pisiform and the adductor

and flexor sesamo~ds—where this age is near

or above the upper chronological age limit for

the children in the study, the num?xr of children

in whom these centers had ossified is too few to

19
li!~-..::

!y -

“f%‘J:{<‘1< u

g -20 -20

6789 10 11 678 8 10 11 67891011 6789 10 11

[k?; 6789 10 11 ‘1’-? 6768 10 11 ‘I<67891011 ‘;[%6789 10 11

i%

!%.20L_s_ co 6789 10 11

Metacarpal I

+20

[’

/ —.

.“-. /“

o

................

F

-20 ~

6789 10 11

+2U

Mets.apal II

L

--1. --,,.

/“

o

“>

-20

67691011

Metacarpal 1[1 +20

I

,/”

--\._

o

“<

.........

-20 ~

67 S291011

CHRONOLOGICAL AGE CHRONOLOGICAL AGE CHRONOLOGICAL AGE

IN YEARS

CHRONOLOGICAL AGE

IN YEARS IN YEARS IN YEARS

—Boys. Male Standar,l

---- Girls.Male Standarti

,......, ~rk+e~l~ Equivalent

Figure 10. Mean difference in months between bone-specific skeletal end chronological ages for the 31 hand-wrist bones for boys and

girls on the male standard and female equivalent means for girls, by chronological age in yeers: United States, 1963-65.

20
[z6789 10 11 :+K6789 10 11 :+K6789 10 11 :+K67691011

[E6789 10 11 ‘:E67691011 ‘:K6789 10 11 ‘:E6769 10 11

Oistal Phalanx II

+20

[

,/

-“1

“--. /

Distal Phalanx I[ I Oistal Phalanx IV Oktal Phalanx V

+20

r

/

+20

[

,/

+20

[

-. /’

\ /“ -“\.. _./

.—.

-“\._./”

t

O-’-%. \ Ot’\ Ot\ Ot-

-20 ~

6789 10 11

CHUONOLOGICALAGE

IN YEARS

Pisifonn +40 \

l\

‘\,

‘... \

+20 .,

“..., ‘\._-/.

...

$.,

%,.

.,.

0 ...

....

...

.....

%

-zo~

6789 10 11

CHRONOLOGICAL AGE

IN YEARS

-zo~ -zo~ -20 ~

6769 10 11 6789 10 11 6789 10 11

CHRONOLOGICAL AGE CHRONOLOGICAL AGE CHRONOLOGICAL AGE

IN YEARS IN YEARS [N YEARS

Adductor Sesamoid

+60 ~

6789 10 11

CHRONOLOGICAL AGE

IN YEARS

Flexor Sesamold

+60 j67B9 10 11

CHRONOLOGICAL AGE

IN YEARS

Figure 10, Mean difference in months between bone-specific skeletal and chronological ages for the 31 hand-wrist bones for boys and

girls on the male standard and female equivalent means for girls, by chronological ages in years: United States, 1963-65-Con,

21
provide reliable estimates of their skeletal maturity. Particular attention is directed to the

findings shown in figure 10; these findings are

similar for each bone, with a few exceptions to

which reference will be made later. The differences between the mean values for boys and girls

(female equivalent values) are smaIl at aH ages.

However, the differences between the mean skeletal ages for the boys and the mean skeletal ages

for the girls (when assessed as boys) increase

fairly refgtlarly from about 15 months at the

chronological age of 6 years to about 32 months

at chronological age 11 years. The exceptions

to the above pattern are bones that ossify relatively late. For the latter, age ranges occur

during which the comparisons are between most

of the girls but only a few of the boys. The boys

included in these comparisons are those who are

skeletally advanced relative to chronological age.

Consequently the sex differences between the

means are small, particularly a; younger chronological ages. This effect is present for the ulna

(6-7 years), the pisiform, and the adductor and

the flexor sesamoids.

Mean bone-specific skeletal ages for girls

(female equivalent values) are generally higher

than the corresponding bone-specific skeletal

ages for boys, particularly among older

children-of chronological ages 9-11 years (at

their last birthday). Among these older children,

about one-half of the 89 mean dinferences in

bone-specific skeletal age between boys and girls

(for whom reIiable national estimates are available from this survey) exceed the 95-percent

confidence limits for such estimates —are statistically significant at the 5-percent probability

level. For three-fourths of these differences

which are statistically significant, the mean

bone-specific skeletal ages for the girls exceed

those for boys of corresponding chronological

ages. By chronological ages 10 and 11 bonespecific skeletal age means for girls are significantly (statistically) mo :e advanced than those

for boys, with few exceptions. Of the 28 bones in

which the onset of ossification is relatively early

the mean differences in bone-specific skeletal

age between the sexes only for the radius, ulna,

trapezoid, triquetral, lunate, a~d scaphoid are

negligible at chronological age 10 years; while

at chronological age 11 years there are three

which are negligible—the triquetral, lunate, and

scaphoid.

Among younger children (chronological ages

6-8 years), there is no consistent pattern. About

one-third of the 86 mean differences in bonespecific skeletal ages between boys and girls

(for which reliable national estimates are available from the survey) are large enough to be

statistically significant at the 5-percent probability level, and of these, the means for girls

are as likely to exceed as be less than those for

boys. After the age of 9 years girls are more

likely to exceed boys in (bone-specific) skeletal

age.

The variability of these bone-specific skeletal ages, as indicated by the standard deviations

and the interquartile range (55- P25) tends to increase irregularly with age (tables 6-8). The

skeletal maturity levels of the lunate for boys

and the proximal phalanx I for girls are more

variable than those of the other bones. A similar

tendency is not present for the triquetral despite earlier reports that the levels of maturity

of this bone are very variable.45’70

When using the Greulich and Pyle Atlas,

many workers follow the instructions of the authors in assigning bone-specific skeletal ages

before combining these to obtain a single skeletal age for each hand-wrist area. This combination is necessary because, in dI_II(J~~ every child,

hand-wrist bones differ in skeletal age. These

differences are partly genetically determined 48371’73 and are not entirely due to the

effects of illness and other environmental factors which were emphasized by Todd. 45 Various

combinations of the same bone-specific skeIetal

ages yield different area skeletaI ages but it is

not known which method of combination is the

best. 74

Bone-specific skeletal ages are needed to

calibrate the Greulich-Pyle Atlas and to assist

recognition of clinical conditions in which maturation is dysharmonic. 75-77 In these coalitions, particular bones differ markedly in maturity from the other bones of the same handwrist. Despite this need, the only reported

bone-specific data for United States children are

those of Peritz and Sproul. 7* Their sample ineluded Ottkland children of slightly above average

socioeconomic status who were within 2.5 per22
centile points of age-specific and sex-specific

medians for stature. Adjusted mean bone- specif -

ic skeletal ages at the chronological age of 6.5

years were obtained from cross-sectional data

between 5 and 9 years. Means were reported for

four selected bones in white children (80 boys

and 84 girls) and black children (33 boys and

36 girls). Neither the basis for selection of these

particular bones (triquetral, lunate, proximal

phalanx 111, and distal phalanx III) nor the mean

skeletal ages for the hand-wrist areas were reported. These data indicate a tendency for the

triquetral to be advanced in girls and for the

lunate to be retarded in all groups in relation

to the other bones selected. These findings for

the lunate among girls, but not those for the triquetralj have been confirmed in the present study.

Means and standard errors of differences between bone- specific skeletal ages and the mean

skeletal ages for the same hand-wrists have

been reported for normal Australian children of

British ancestry. 79 These children were similar

to lJ.S. white children in many parameters of

growth, maturation, and illness experience 80

but they were 4 years old; consequently, these

data are not directly comparable with those of

cycle 11,

Normative data have not been reported concerning the spread of bone-specific skeletal ages

within the hand-wrist areas of individual children.

Possibly, the range fro-m the least mi~ture to the

most maw re bone varies with the difference

between hand-wrist skeletal age and chronological

77 age. Pyle et al. 81 have suggested graphing

the most mature and the least mature bonespecific skeletal ages in addition to the mea I

skeletal age, and that the most mature age indicates the child’s potential rate of skeletal

maturation. This attitude agrees with Todd’s 45

statement that the principle of assessment is

the utilization of the most advanced centers,

not the average of all. Few have followed the

suggestion of Pyle et al. 81 because normative

data are lacking and because the usefulness of

these graphs has not been demonstrated.

The survey findings are presented in table 9

as percentiles in the distributions of the ranges

of the bone-specific skeletal ages for boys and

girls at each year of chronological age for the

total grcmp and also within approximate years

of skeletal age (hand-wrist). It should be noted

that these are the ranges of skeletal ages that

could be assigned. In some children a few individual bones were already adult while in other

children some had not ossified. Consequently

these are not the complete ranges of skeletal

maturity but are the ranges of ages tha: could

be assigned. The interquart ile ranges (~75‘~25)

for boys and girls at chronological ages 6-8 years

differ by less than 1 month and are approximately

the same at chronological age 9 years, but among

older children of ch.ronoiogical ages 10 and 11

years, they are smaller by 2 to 3 months for boys.

Within chronological age gro~ps, the median

ranges tend to decrease with chronological age

in boys but there is no apparent trend for girls.

In each sex, there is some skewness to che right.

These data are shown graphically in figure 7.

The data in table 9 show that the ranges are

independent of skeletal age within chronological

age groups.

The present national study is the first in

which the data allow a good estimate of the extent to which bone-specific skeletal ages vary

within individual hand-wrists. If the 95th percentile level may be accepted as the upper limit

of normal, then the normal range is greater in

boys than in girls. In boys, the range of variation decreases with chronological age from 51

months at age 6 years to 39 months at age 11

years. In girls, there is no evidence of a trend

with age—the 9Sth percentiles are between 41

and 47 months for each age from 6 through 11

years.

DISCUSSION

Two subjects that will be emphasized in this

discussion are the nature of the sampIe and how

skeletal ages were obtained for each participant.

The 7,119 children who were examined during the

period July 1963 through December 1965 were

96 percent of the national probability sample of

7,417 noninstitutionalized children selected for

this survey. However, 157 of these examined

children were not radiographed or had unsatisfactory radiographs. It was assumed that the distribution of skeletal ages for these 157 chiIdren

would be similar to that of the children whose

23
radiographs were assessed. After inflation of the

sample findings to the population from which the

sample was drawn by differential weighting which

compensated for the 298 nonrespondents (appendix I), the data provided close estimates of skeletal maturity for the total noninstitutionalized

United States population aged 6-11 years in 1963-

65. The national sample was known to be representative and the examined group was closely

representative of that group in the population with

respect to age, sex, race, geographic region,

size of place of residence, and mobility of place

of residence.

Skeletal ages of the individual bones in the

right hand-wrist area were assessed by medical

students who had been trained and were carefully supervised by Dr. S.1. Pyle. Their reliability is shown to be acceptable in comparison with

reported data (appendix 11). Assessments were

made by comparison with the standards of Pyle

et al,b This set of standards was derived primarily from the Greulich and Pyle Atlas 5 and

was compiled for this national survey. The assessors knew neither the sex nor the chronological age of the child; consequently, a possible

source of bias was removed. All the children

were assessed using male standards, thus providing reliable estimates of sex differences in

maturity status. Later, the data for the girls were

adjusted, bone by bone, for the reported sex dif -

ferences in skeletal maturity.c

The Need for a Survey

Skeletal age is commonly assessed because

of the need for a measure of biological age when

appraising the progress of children in stature,

weight, or specialized dimensions such as those

of interest to orthodontists. Furthermore, a biological age measure is important in screening for

endocrinopathies, for example, hypothyroidism,

and in selecting ages for surgical induction of

epiphyseal fusion in children whose legs are unequal in length. Others use these assessments to

monitor intervention programs or the effects of

hormones or drugs, for example, in the management of children with hypothyroidism or excessive stature. Skeletal age assessments are used

aIso to predict the mature statures of individuals

from childhood parameters.

These data from the national survey were

needed because the distribution of hand-wrist

skeletal ages was unknown for United States chil -

dren. The Greulich-Pyle Atlas5 is satisfactory

for many purposes, but it is based on radiographs

of highly selected upper class white children who

lived in Cleveland and were born between 1917

and 1942. Clearly, this sample was not representative of the total United States population. In

addition, possible differences in maturity status

reflecting racial and socioeconomic factors are

poorly documented; a subsequent report cm the

present data will address these subjects.

It could be suggested that a single fixed scale

is adequate for all countries and for all time.

The difficulties that could arise from this can be

illustrated using age at menarche as an analogy.

In Norway, the mean age of menarche decreased

from 17.1 years in 1844 to 13.3 years in 1952.82

If a scale developed a century ago for determining whether age at menarche was “normal” were

still in use today, almost all Norwegian girls

would be considered precocious. It would be necessary for clinicians and others to adjust the

scale for the secular changes that had occurred.

This would involve knowing the extent of the

changes in the means and the distributions. A

national survey would be indicated to obtain the

necessary data. Apart from possible secular

changes, particular racial and socioeconomic

groups in the United States may have levels of

skeletal maturity different from those of the

Greulich-Pyle standards; such differences should

be documented and their causes sought.

Skeletal Age (Hand-Wrist)

The skeletal ages of the boys in the national

survey tended to lag behind their chronological

ages when assessed against the HES Standard.

The mean difference increased from 2.5 months

at age 6 years to 13.8 months at 11 years. When

the girls were assessed against the same male

standards, their mean skeletal ages were consistently aheud of the chronological ages by differences ranging from 12 months at 6 years to

18.5 months at 11 years. When skeletal ages for

the girls were adjusted to become approximately

equivalent to what they would have been if assessed against female standards, the mean skel24
etal ages lagged behind the chronological ages.

The difference was only l.Omonth at6 years but

increased to9.8 months atll years.

The distributions of skeletal age were essentially normal for each annual interval. The standdard deviations ranged from 9.9 to 13.8 months and

tended to increase with chronological age for

girls but not for boys. Variability, measured by

the range from the 25th to the 75th percentile,

was lower at 10 years for boys and 8 and 11 years

for girls than at other ages. Modal radiographs

for boys and girls of these ages have similar

maturity characteristics. The 90-percent ranges

(Sth to 95th percentiles) varied between 35 and

42 months for boys and 33 and 40 months for

girls. The lack of a clear-cut tendency for skeletal age to become more variable with increasing

chronological age is probably due to the nature

of the scale used to assess skeletal maturity.

This scale was derived from modal radiographs

for chronological age groups which would tend to

obscure the effects of variation between individuals in the timing of puberty.

The present data can be compared with previously reported data for various groups of United

States children. The standards of Flory 61 for

upper class white Chicago children are about one

year below the Greulich-Pyle standards in each

sex. These differences tended to increase with

age for the boys and to decrease for the girls.

The close correspondence between the data of

Simmons57 and the Greulich-Pyle standards helps

substantiate that the Greulich - Pyle standards

were modal because many radiographs were used

in both these studies. In addition, the mean levels

for the children in the Harvard Growth Study

closely matched the Greulich-Pyle standards.s

The accuracy of selection by Greulich and Pyle is

attested to by the fact that the Todd standards45

are about 0.5 year below the Greulich-Pyle standards. This would be expected because Todd used

radiographs of children from all socioeconomic

levels.

The mean skeletal ages of upper and middle

class white boys in Philadelphia exceeded the

mean chronological ages by small amounts that

increased with age to 0.65 year at 11 years. 58

The mean skeletal ages for the girls in this study

were closer to Greulich-Pyle standards. For middle class white boys in Nebraska, the mean skeletal ages were below the mean chronological ages

by more than one year at 6 and 7 years; subsequently the differences decreased with age.sg The

mean skeletal ages for the girls in this Nebraska

study were below the Greulich and Pyle standards

by about 0.5 year at most ages.

In other middle class white children, themedian skeletal ages were about 0,6 year below the

Greulich-Pyle standards from 6 through 11

years. 60 In general, the previous data show a

tendency for the skeletal ages of boys to be below Greulich-Pyle standards which is in agreement with the national survey findings. Nevertheless, the national survey data show an increasing

lag of skeletal age with advancing chronological

age that is the opposite of the trends reported

from smaller and less representative samples.

Comparisons Mween these studies of generally middle class children could indicate a possible reverse secular trend, but this conclusion

is very tenuous because sampling methods varied

between studies and comparability between assessors was rarely established. This possible

trend is also inconsistent with the findings in the

present national survey data which show greater

retardation in skeletal maturity in the older, and

consequently, earlier born children.

The relative variability of the distributions

of skeletal age from the present national survey

is greater than that found in the groups studied

by Simmons 57 and Greulich and Pyle.5 This would

be expected because of differences in sampling

and in schedules for examination. The children

included in the earlier studies were relatively

homogeneous socioeconomically. Furthermore in

those previous studies there was a narrow spread

of chronological ages within each age group because children were examined within 2 weeks of

their birthdays. In contrast for children in the

present national study, chronological age was

essentially uniformly distributed throughout the

entire year. The effects of such differences in

schedules for examinations on recorded data have

been discussed by Healy 83 and Goldstein and

Carter. 84

Onset of Ossification

National estimates of the median number of

bones ossified is slightly higher in girls than in
boys at corresponding ages. Advancement of girls

is apparent also in the percentages within chronological age groups, with fewer than24 bones ossified. Furthermore, in the girls 1 percent of

bones were’’adult” at9 years and this increased

to 12 percent at 11 years, while not a single bone

of any boy was judged adult. While these data are

cited to confirm the maturational advancement

of girls demonstrated by skeletal age, observations of onset of ossification alone (by combining

the number of centers ossified) can be an effective assessment technique in preschool children

only.85

The national study estimates modal ages

of onset of ossification among children in the

United States for the distal ulnar epiphysis,

trapezium, and trapezoid in boys, for the adductor

sesamoid in girls, and for the pisiform in each

sex. Earlier studies among selected groups of

children in this country were based on smaller,

less representative samples, yet the mean ages

from the national survey are within the range of

those previously reported “modal” ages. The national survey values were within 0.3 year of those

reported by Greulich and Pyle 5 with the exception of the pisiform. The modal ages for this bone

in the national survey children were later by 0.8

year in boys and 0.4 year in girls. The national

survey radiographs were of excellent quality and

an independent check showed that very small

areas of ossification in the pisiform were being

recognized. These comparisons with the onset

of ossification data of Greulich and Pyle are of

particular interest because the latter used many

of the same radiographs both in the construction

of the Greulich and Pyle Atlas and for their onset

of ossification data.

Bone-Specific

Skeletal Ages’

The Health Examination Survey provides national estimates of means and standard deviations

for each of the 31 hand-wrist bones when both

sexes were assessed against male standards and

also after the values for the girls had been

changed to female equivalent values. The sex

differences between the means were small when

the latter values were used but there was a tendency for the skeletaI ages to be somewhat greater

in the girls than in the boys at later chronological

ages.

The differences between means for the boys

and girls, when both were assessed as male, increased fairly regularly with age from age 8

years except for bones that were relatively late

to ossify (ulna, pisiform, and adductor and flexor

sesamoids). The increase in the mean differences

between the sexes was more rapid in the national

findings, both for skeletal age (hand-wrist) and

for the individual bones, than that reported by

Greulich and Pyle 5 (figures 11 and 12). These

comparisons between the two studies are based

on most of the girls but only the rapidly maturing

boys (only the ones in whom the bones had ossified and therefore could be assessed). There

are no substantial data for bone-specific skeletal

ages in United States children with which the

present findings can be compared. They are important, however, for several reasons: they provide for a better description of clinical syndromes

in which skeletal maturation is dysharmonic ,77

they provide a better basis for comparison with

other methods of rating skeletal maturation, they

can be used as a basis for the development of

scoring systems of skeletal maturity, they allow

the identification of bones particularly sensitive

in maturation to environmental effects, and they

can identify possible racial or other genetic patterns of maturation within hand-wrist areas.

Ranges of Bone-Specific

Skeletal Ages

Use of the range of skeletal ages fr~m the

most mature to the least mature bone has been

suggested for monitoring the effects of illness

and malnutrition. 81 The usefulness of this ap.

preach has not been satisfactorily demonstrated

and normative data were lacking. These national

survey data fulfill a real need in supplying reliable estimates of percentiles for the ranges of

bone-specific skeletal ages at each year of chronological age for the United States child population. It should be noted that these are the ranges

of skeletal ages that could be assigned. In some

children a few individual bones were already

adult while in others some had not ossified. Consequently these are not the complete ranges of

26
skeletal maturity but are the ranges of ages that

could be assigned.

The sex differences in these ranges were

small, and these ranges were independent of

skeletal age within chronological age groups despite a contrary suggestion based on data relating to onset of ossification from the Ten-State

Nutrition Survey.

Sex-Associated Differences

in Skeletal Maturity

Cme major contribution to knowledge from

this national survey concerns sex differences.

This possibility resulted from the nature of the

sampling and from the fact that both sexes were

wwwssed against a single set of standards without the assessors knowing the sex of thechildren.

In figure 11, sex differences in skeletal age in

months (male less female) are graphed against

chronological age. These graphs compare the

findings from the national survey with those reported by Pyle et al .6 The two reports are in

essential agreement until 8 years in the whole

hand-wrist; later the differences from the national survey exceed those reported by Pyle et

al. by increasing amounts.

These comparative findings for the whole

1:

!5 :3....................

< 12 Pyleet al. (1971)

z

u

+

!?6

s

o. I I I I I

6 7 8 9 10 11

cHRONOLOGICAL AGE IN YEARS

Figure 11. Mean differences between boys and girls in skeletal

age (hand-wrist) on the male HES standard for United Statas

children from the national study (1963-65) and from the data

of Pyle et al.6 by chronological age.

hand-wrist are reflected in those for the bonespecific skeletal ages. Only selected graphs of

the latter have been reproduced because of the

close similarity between the differences for some

bones (figure 12). The patterns for the radius

closely resembled those for the ulna; both sources

(national survey and Pyle et al.) are in general

agreement up to 9 years, after which the differences from the national survey become markedly

larger. The data for the capitate, hamate, and

triquetral are similar; the differences between

the present data and those of Pyle et al. are

small until 10 and 11 years, when those from

the present survey markedly exceed those of

Pyle et al. In the data of Pyle et al.,6 the differences for the lunate and trapezium were irregular across age; this same irregularity is not

present in the national survey data. In the scaphoid and trapezoid, there were marked differences

in trends rather than in levels between the two

studies. The differences reported by Pyle et al.

were nearly constant across age; those from the

national survey increased gradually.

The patterns were similar for all the metacarpal both in the national survey data and in

those of Pyle et al. Data for metacarpal 11 have

been graphed as an example (figure 12). The two

reports agree until 9 years, after which the differences between the sexes from the national survey markedly exceeded those reported by Pyle

et al. The proximal phalanges all folIowed similar patterns, and the data for proximal phalanx

III are shown. For this, the two studies were in

agreement until age 8 years; after that the sex

differences from the national survey exceeded

those reported by Pyle et al. by amounts that increased with age.

The patterns of sex differences across age

for each middle phalanx and distal phalanx were

similar. The differences from the national survey resembled those reported by Pyle et al. until

age 9 years; later sex differences from the national survey became markedly larger. The findings for middle phalanx IV are shown as an example (figure 12). The data for the pisiform

showed slightly greater sex differences in the

national survey children, but the samples available for study were unrepresentative because

only early maturing boys have the pisiform ossified during the age range considered.

27
RADIUS

r

o~

6789 10 11

36r METACARPAL II

o~

6789 10 11

CHRONOLOGICAL AGE IN YEARS

36 CAPITATE

r

30

24

18

~J

/

/“

. . . . . . . ..-

. ...-.’

12 ‘---

o~L678 9 10 11

36 PROX. PHALANX Ill

30

24

18

v

.....

.....

. . ...+- . . . . . . . . .. . . .

12

6

I

oL——L———

6789 10 11

CHRONOLOGICAL AGE IN YEARS

36 LUNATE

r

30

24

J

.

18 .....

. . . . ...”

. . . . . . . . .

..,, ~.

12

$., ;:

... ...

‘<

6 -

ob_LJJ_L

67891011

36 SCAPHOID

r

30

24

1

...

,,.

18

//

,, >...”’’””’”’

“t

J_Lu_U_

67891011

CHRONOLOGICAL AGE IN YEAR:

36 r

MIODLE PHALANX IV

— United States (1963.65)

.. . . . . . Pyle et al. (1971)

‘t

OLLL——.L

67891011

CHRONOLOGICAL AGE IN YEARS

Figure 12. Mean differences between boys and girls in selected bone-specific skeletal ages on male HES standard for United States

children from the national study (1963-65) and from data of Pyle et el.a by chronological age.

Other Measures of

Biological Age

Skeletal age can be applied over wider age

ranges than other possible measures of biological age. Two common biological ages are related to menarche and peak height velocity (the

midpoint of the year with the largest increment

in stature during pubescence). These two biological ages can be applied only to children who

are near the end of growth and for whom serial

data are available. Consequently they are of

limited use in a clinical setting. Furthermore

age in relation to menarche is limited to girls.

Body shape does change during maturation

with perhaps the most obvious alterations being

the pubertal growth in the shoulder width of boys

and the hip width of girls. These and other shape

measures are inappropriate as biological ages

because they differ widely even among people

who are clearly adult.

Secondary sex characteristics have received

much attention. Grading methods will be described, but these are useful only during the age

ranges when they discriminate among individuals,

that is, about 9-16 years. Dental maturity can

be graded either by counting the number of teeth

erupted, recording which teeth are erupted, or

assessing the degree of root formation of individual teeth. The latter provides an uninterrupted

scale over a wide age range but it requires specialized radiographic equipment and training.

There are also some difficulties in using dental

maturity as a biological age. Other biological age

28
scales agree in showing that girls are more

advanced than boys within chronological age

groups. However, sex differences in deciduous

dental development are not significant ,s6-89and

dental development has not previously been found

to be related closely to either stature or skeletal age in preschool children. 87 Findings from

the Health Lamination Survey in 1963-65 among

6-11 year-old children in the United States show

that tooth eruption is more rapid in girls than

boys.go Further assessment of sex differences

in the rate of maturation for permanent teeth

is complicated by the fact that these sex differences vary among teeth. 91’92

For these reasons, skeletal age has been

used more commonly than other biological ages.

Its usefulness will be increased further by the

reliable estimates for the whole United States

population aged 6-11. years provided by this national survey.

SUMMARY

This report contains national estimates of

the skeletal maturity status of noninstitutionalized

children 6-11 years of age in the United States

based on assessments of radiographs of the right

hand-wrists of children examined in the Health

Examination Survey of 1963-6S. A probability

sample of 7,417 children representative of the

nearly 24 million noninstitutionalized children

in the United States was selected. Of these, 7,119

children, or 96 percent, of the sample were examined, and radiographs suitable for assessment were obtained from 6,962 (98 percent of

the examined group, or 94 percent of the total

sample).

These radiographs were assessed by specially trained medical students who knew neither

the age nor the sex of any child whose radiograph was assessed. This removed several

sources of bias. All assessments were made

against male standards; later the skeletal ages

were adjusted, bone by bone, using the sex-associated differences in maturity reported by Pyle

et al.6

When assessed against the specially assembled HES Standard, the skeletal ages of the boys

tend to be less than their chronological ages by

amounts that increased with chronological age

from a mean difference of 2.5 months at 6 years

to 13.8 months at 11 years. The differences between skeletal and chronological age in girls are

smaller than in boys but are in the same direction after the skeletal ages of the girls had been

adjusted for the reported sex differences. The

increase in these differences with chronological

age for girls is from 1.0 month at age 6 years

to 9.8 months at 11 years. These important findings indicate that the Greulich and Pyle Atlas 5

scale does not match the modal skeletal ages for

the total United States noninstitutionalized child

population because the Atlas was based on a study

group that was not representative of that total

United States population.

As expected, skeletal maturation tended to

be more advanced in girls than in boys when both

were assessed against the same male standards

or when the numbers of centers ossified were

compared.

The distribution of skeletal ages within chronological age groups is close to normal with the

standard deviations tending to increase with age

for the girls but not the boys.

These national survey data provide means

and standard deviations for the skeletal age of

each of the 31 hand-wrist bones. For the first

time, there are reliable national estimates for

these levels in United States children (6-11 years)

and the normal ranges of bone-specific skeletal

ages within the hand-wrists of individual children are known.

A major advance in knowledge from the present data relates to sex-associated differences

in skeletal maturity when radiographs of boys

and girls are assessed against a single set of

standards. These differences for the hand-wrist

as a whole and for most of the individual bones

match closely those reported by Pyle et al.,6 up

to 8 years. The sex-associated differences estimated from the national survey data were considerably larger at later ages.

Necessarily, comparisons with previous reports from smaller less representative samples

have been made throughout this report. It should

not be overlooked, however, that the present data

allow reliable estimates of skeletal maturity for

the total population of the United States within

the age range considered. Such estimates are

not available for any other country.

29
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31
study of both retarded and accelerated hand growth in

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1962.

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1943.

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7’oJohnston, F. E., Whitehouse, R. H., and

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72 Pryor, J. W.: Ossification of the epiphyses of

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73 Garn, S. M., Rohmsnn, C. G., and Davis, A. A.:

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77poznmski, A. K., Gmn, S.

and Sandusky, S. T.: Dysharmonic

hand in the congenital malformation

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80 Roche, A. F., Davila, G. H., and Eyman, S. 1,.:

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82 Tanner, J. M.: Growth At Adolescence. Oxford.

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83 Healy, hl. J. R.: The effect of age grouping on

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85 Yarbrough, C., Habicht, JrP., Klein, R. E., and

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86 Doering, C. R., and Allen, hi. F.: Data on

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32.
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95Moore, W. hL: Comparability in skeletal

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Growth of thr normal trunk in boys and girls during the

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47 A:1554-1564, 1965.

97 Gray, S. W., and Lamons, F. P.: Skeletal development and tooth eruption in Atlanta children. Am. j.

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98Acheson, R. M., Fowler, G., Fry, L. I.>Janes,

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99 Andersen, E.: Skeletal maturation of Danish

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10OMazess, R. B., and Cameron, J. R.: Skeletal

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10 lMainland, D.: Evaluation of the skeletal age

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102A nderson, M.: Growth, overgrowth, and

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103Moed, G., Wight, B. W., and Vandegrift, H. N.:

Studies of physical disability: reliability of measurement

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1962.

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in Philadelphia children. Hum. Biol. 35:192-201, 1963.

105Sproul, A., and Peritz, E.: Assessment of skeletal age in short and tall children. Am. j. Phys. A nthropol. 35:433-439, 1971.

106Demisch, A., and Wartmann, P.: Calcification

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1956.

*07 Koski, IL, Haataja, J., and Lappalainen, M.:

Skeletal development of hand and wrist in Finnish children. Am. J. Phys. Anthropol. 19:379-382, 1961.

108Hansman, C. F., and Maresh, M. hi.: A longitudinal study of skeletal maturation. Am. J. Dir. Child.

101:305-321, 1961.

33
LIST OF DETAILED TABLES

Page

Table 1.

2.

3.

4.

5.

6.

7.

8.

9.

Mean, standard deviation,and standard error of mean for skeletal age (hand-wrist)

of boys and girls,by chronological age in years at “lastbirthday,mean and standard deviation for skeletal age (hand-wrist) for boys and girls within 6-month

chronological age intervals, and number of boys and girls at each chronological

year of age: United States, l963-65---------------------------------------------

Mean and standard deviation for skeletal age (hand-wrist) in months of boys and

girls, by chronological age in months: United States, 1963-65-------------------

Percent distribution and selected percentiles for skeletal age (hand-wrist) in

months of boys and girls by chronological age in years at last birthday: United

States, l963-65-----------------------------------------------------------------

Percent distribution for skeletal age (hand-wrist) in months of boys and girls

by chronological age at last birthday in 6-month intervals: United States,

l963-65-------------------------------------------------------------------------

Percent of boys and girls showing the number of radio-opaque hand-wrist bones—

ossifying and adult—by chronological age in years at last birthday; United

States, l963-65-----------------------------------------------------------------

Mean, standard deviation, and standard error of mean of bone-specific skeletal

ages for the 31 individual hand-wrist bones of boys and girls and number of

children,by chronological age in years at last birthday: United States,1963-65--

Mean and standard deviation of bone-specific skeletal ages for selected handwrist bones of boys and girls, by chronological age in 6-month intervals: United

States, l963-65-----------------------------------------------------------------

Selected percentiles in the distribution of bone-specific skeletal ages for each

of the 31 hand-wrist bones of boys and girls,by chronological age at last birthday: United States, l963-65-----------------------------------------------------

Selected percentilesti the distribution of the individual child’s range in bonespecific skeletal ages for the radio-opaque (not adult) bones in the hand-wrist

and girls, by chronological age in years at last birthday: United

~at;;Ysl963-65-----------------------------------------------------------------

36

37

38

40

43

44

50

52

56

35
Table 1. Mean, standacd deviation (S ), and standard error of mean (Sx) for skeletal age (hand-wrist)

of boys and girls, by chronological?iage in years at last birthday; mean and standard deviation for

skeletal age (hand-wrist) for boys and girls within 6-month chronologicalage intervals, and number

of boys and girls at each chronologicalyear of age: United States. 1963-65

Chronologicalage

6 years---------------------

7 years---------------------

8 years---------------------

9 years---------------------

10 years--------------------

11 years--------------------

Age in 6-month intervals

6

7

8

9

years:

O-5 months----------------

6-11 months---------------

years:

O-5 months----------------

6-11 months---------------

years:

O-5 months----------------

6-11 months---------------

years:

O-5 months----------------

6-11 months---------------

13 years:

O-5 months----------------

6-11 months---------------

11 years:

O-5 mo~ths----------------

6-11 months---------------

Boys (male Girls (male Girls (female

standard) standard) equivalent value)

Mean Sx 8X Mean Sx $x Mean Sx .9X

75.5

86.9

96.9

105.8

113.4

124.2

73.9

78.1

84.4

90.3

94.6

‘39.9

Lu3.7

L08.5

L1l.6

L16.2

L21.1

L27.9

Skeletal

11.16

11.21

11.25

10.91

9.87

12.53

11.46

10.83

10.77

11.62

11.47

11.94

11.19

10.66

9.75

9.99

11.29

13.37

0.47

0.55

0.45

0.43

0.44

0.55

---

---

---

---

---

---

---

---

---

---

---

---

age (hand-wrist)in months

90.0

101.2

111.3

122.7

137.7

156.5

88.1

92.7

99.1

104.2

109.0

L14.8

L19.1

L27.7

L33.9

142.7

153.9

L59.8

12.15

11.59

11.97

14.29

16.25

14.45

11.58

12.62

12.29

10.85

12.97

10.82

13.19

15.41

15.20

17.32

14.57

14.66

0.53

0.48

0.53

0.68

0.70

0.61

---

---

---

---

---

---

---

---

---

---

---

---

77.(

88.1

96.:

107.i

116.8

128.2

75.1

79.7

86.1

90.2

95.0

99.8

104.1

LLO.8

L14.9

119.8

L26.4

L29.9

10.40

10.09

10.36

12.54

13.78

11.84

9.87

10.85

10.68

9.39

11.30

9.41

11.53

13.36

13.04

14.53

11.93

11.91

0.45

0.42

0.46

0.60

0.59

0.50

---

---

---

---

---

---

---

---

---

---

---

---

Population

5_J52

Number in

thousands

2,082

2,074

2,026

2,012

1,963

1,924

---

---

---

---

---

---

---

---

----

---

---

---

2,016

2,010

1,960

1,945

1,904

1,868

---

---

---

---

---

---

---

---

---

---

---

---

36
Table 2. Mean and standard deviation for skeletal age (hand-wrist) in months of boys and girls,

by chronological age in months: United States, 1963-65

——

Sex and

year of

chronological age

%&E&

6 years-----

7 years -----

8 years -----

9 years -----

10 years----

11 years----

12 years----

6 years -----

7 years-----

8 years -----

9 years -----

10 years----

11 years----

12 years----

Boys (male

standard)

6 years -----

7 years -----

8 years -----

9 years -----

10 years----

11 years----

12 years----

-=a&- Girls male

6 years -----

7 years -----

8 years -----

9 years -----

10 years----

11 years----

12 years----

0

68.1

81.9

87.0

101.3

111.6

117:2

131.5

90.1

97.6

108.7

115.7

131,0

151.8

161.7

10.41

11.98

10.24

12.08

8.67

9.53

15.46

8.18

12.88

9.43

12.77

17.09

14.79

11.95

ZIz

71.1

82.5

95.1

104.7

112.0

121.2

...

83.3

94.6

108.2

120.7

128.4

152.2

...

75.3

85.6

96.0

103.9

109.8

118.8

...

87.0

97.6

107.2

114.5

134.9

151.5

...

Month in chronological year of age

3 4 5 6 7 8

Mean skeletal age (hand-wrist) in months

74.3

83.2

97.3

103.1

110.8

121.7

...

85.7

102.7

109.5

120.6

134.9

152.0

...

74.3

85.1

92.5

102.7

112.0

124.0

...

87.7

103.3

110.1

119.7

137.3

155.7

...

77.0

87.6

97.1

106.8

114.1

123.6

...

94.1

100.8

110.6

124.8

139.2

162.5

...

76.3

88.4

98.9

105.7

115.8

124.3

...

91.2

104.4

114.4

128.2

134.8

155.6

...

77.4

89.5

98.5

107.3

114.4

127.2

...

91.5

102.2

114.2

121.6

138.6

156.5

...

77.1

88.5

102.3

1.07.9

115.9

129.8

...

90.4

103.7

112.2

125.3

141.5

157.7

...

13.00 11.45

10.55

11.54

11.76

9.67

10.76

. . .

9.72

11.75

16.37

13.82

14.27

15.23

...

11.01

9.92

11.30

9.01

13.50

...

9.01

10.84

13.10

9.83

15.32

16.20

...

Standard deviation of skeletal age in months

10.00

10.48

11.79

11.97

12.24

10.83

...

12.39

12.55

13.01

12.36

13.66

15.67

...

11.69

11.93

13.68

9.57

8.53

11.85

...

13.16

14.66

12.48

15.02

16.35

11.90

...

11.17

9.01

11.47

9.36

9.41

11.32

...

13.25

11.73

10.63

15.15

14.30

14.22

...

10.42

11.89

10.62

9.19

10.23

10.11

...

10.85

9.17

9.92

17.28

13.85

17.23

...

9.67

11.33

12.00

10.87

11.42

12.00

...

13.78

10.57

12.42

13.02

18.22

14.55

...

11.15

9.70

10.60

11.17

8.08

16.06

...

12.46

10.86

7.74

14.03

16.88

14.73

...

9

79.3

91.2

100.7

109.9

116.9

128.1

...

92.0

103.8

114.6

128.0

147.4

159.2

...

9.41

11.61

9.47

11.61

10.43

15.72

...

13.57

11.97

9.87

14.09

19.34

16.53

...

-Ill

78.1

93.8

99.7

110.2

119.2

126.8

...

93.3

105.4

116.1

131.4

148.6

162.2

...

11.38

12.61

12.26

13.33

11.42

12.44

...

12.79

11.57

12.48

16.57

17.81

13.53

...

80.6

89.5

99.7

110.4

115.5

129.7

...

97.5

105.7

118.6

131.5

145.6

163.5

...

12.50

11.98

10.93

6.85

7.12

13.43

...

11.66

10.34

12.05

16.74

16.58

10.38

...

37
Table 3. Percent”distributionand selectedpercentilesfor skeletalage (hand-wrist)

in months of boys and girls by chronologicalage in years at last birthday: United

States, 1963-65

Skeletalage (hand-wrist)in months

Below 42-----------------------------

42-47--------------------------------

48-53---------------------------------

54-59---------------------------------

60-65--------------------------------

66-71--------------------------------

72-77--------------------------------

78-83--------------------------------

84-89----.---------------------------

90-95-------------------------Q-------

96-101-----------s------.......------

102-107.-----------------.-----------

108-113------------------------------

114-119-----.............------------

120-125------........................

126-131-------------------.-----------

132-137---------------.--------------

138-143----m-----------.-.-=-----=---

144-149------------------------------

150-155---------------------------- ---

156-161---------.----................

162-167------------------------------

168-173-s----.-----------------------

174-179-----------------------------m180-185------------------s-.---------

186-191---------------------------...

192-195------------------.s-------...

Percentile

P,, --------- --------- ----m---- . . . . . .

-------- -------- -----q-- --q----- .

9: --.-------------------------.

$25 --------- -------- -------s -------- .

5

---------------------------- ------

Approximate test for normality

X:4---------------------------------

Boys-chronological age in years

6 7 8 9 10 11

Percent distribution-male standard

M

2.1

;:!

18.4

21.6

17.6

14.7

:::

0.9

0.3

0.5

.

-

.

.

-

.

.

1.6

2.1

5.3

13.2

17.9

21.5

15.8

1;.;

4:7

0.8

.

.

.

.

.

.

-

94.7 108.2

83.8 95.0

75.6 87.0

68..5 79.1

57.2 69.6

0.2

O.i

M

1;:;

16.8

16.1

20.7

15.6

3.7

0.2

0.3

0.2

.

.

.

.

.

.

-

.

0.4

0.4

2.1

1?::

11.3

21.0

23.4

17.5

4.3

2.1

0.3

0.1

0.2

0.2

.

0.;

.

-

.

-

H

5.1

13.2

;;.:

14:8

6.3

2.1

i:?

0.6

.

-

.

.

.

.

Skeletalage (hand-wrist)in months

113.4 122:1 131.0

107.1 113.9 120.1

98.3 107.6 113.6

89.5 98.8 108.3

75.5 87.4 96.1

0.21 I 0.24 1.42 0.42 0.55

-

-

0.3

1.;

1::;

26.0

18.7

12.1

8.2

~:;

.

M

0.;

.

.

.

150,8

131.6

121.6

115.5

108.9

3.58

38
Table 3. Percent distribution and

in months

selected percentiles for skeletal age (hand-wrist)

of boys and girls by chronological age in years

States, 1963-65-Con.

at last birthday: IJnited

Girls-chronological age in years

6 7 8 9 10 11

Percent distribution-male standard

0.;

::;

1%;

17.8

15.2

14.0

10.8

H

0.6

O.i

.

“

.

.

.

.-

.

0.;

:::

11,7

13.3

11.8

18.5

22.4

11.4

::;

$;

o.i

.

-

.

.

0.;

$;

N

1::;

26.1

23.8

10.7

5.1

;::

0.5

:.;

,

.

.

0.;

.

.

.

0.2

0.2

1.2

;::

1:::

25.5

16.3

13.4

::;

3.1

3.4

1.8

;:;

.

.

o.i

;:;

.

1:::

11.O

13.4

11.0

8.6

1:::

11.1

6.0

:::

0.3

.

-

-

.

-

0.;

0.8

:::

4.0

6.0

J:?

18.6

19.9

11.5

?::

1.5

0.4

Girls-chronological age in years

I I I I I

6 7 8 9 10 11

Percent distribution-female equivalent

0.2

0.6

::;

11.2

15.8

18.0

15.9

14.0

10.6

3.6

1.7

0.2

0.2

-

-

.

;:!

1!:;

13.9

13.9

25.5

18.8

4.5

0.9

0.5

0.1

0.;

0.6

1.9

W

10.1

23.4

26.7

16.5

;::

0.5

0.7

0.2

-

0.;

0.2

;;:

2.2

2?::

21.3

22.8

8.3

N

1.3

0.6

.

.

.

.

-

o.i

-

0.<

0.5

:::

11.4

21.0

15.8

14.2

19.3

&.8

U

0.3

-

::;

2.1

:::

15.2

30.3

19.7

9.4

?:;

M

Skeletialage (hand-wrist) in months

111.9 117.6 130.8 153.9 164.6 177.5 96.9 102.6 112.9 126.4 133.6

99.1 111.0 118.0 129.6 153.4 166.9

145.5

86.1 ;:.: 103.0 112.3 126.2 134.9

89.7 104.1 112.4 120.1 135.8 159.7 76.7 !9;.; 1:;.; :;;.: 129.9

81.5 92.7 106.3 114.3 124.3 149.3 67.5 79:7

71.1 81.0

123.6

91,3 101.6 112,9 127.3 57.1 67.0 78:3 88:3 97:9 110.6

0.28 1.28 1.37 3.46 2.69 ... ... ... ... ... ...

39
Table 4. Percent distribution for skeletal age (hand-wrist) in months of boys and girls by chronological age

at last birthdav in 6-month intervals: United States, 1963-65

-——

Chronological age in months

72- 78- 84- 90- 96- 1o2- 108- 114- 120- 126- 132- 138- 144-

77 83 89 95 101 107 113 119 125 131 137 143 145

Skeletal age

(hand-wrist)

in months

Boys

Below 42--------

42-47 -----------

48-53 -----------

54-59-----------

60-65-----------

66-71-----------

72-77-----------

78-83-----------

84-89-----------

90-95-----------

96-101----------

102-107---------

108-113---------

114-119---------

120-125---------

126-131---------

132-137---------

138-143 ---------

144-149---------

150-155---------

156-161---------

162-167---------

168-173---------

174-179---------

180-185 ---------

186-191---------

192-195---------

Percent distribution of skeletal age—male standard

l.ii

2.0

5.6

1:::

19.3

15.0

14.4

13.8

2.0

0.;

O.z

1.;

:::

9.7

14.6

17.1

26.6

17.1

5.3

0.3

0.6

0.;

1.0

;::

14.6

14.2

19.4

23.8

12.1

1.8

;:!

0.;

0.3

::?

::;

22.3

23.3

22,2

6.5

2.4

::;

0.4

0.3

2.i

4.6

1$::

32.9

18.3

12.2

3.4

1.9

0.5

0.;

0.;

2.4

3.8

9.2

25.0

27.0

17.5

9.2

2.3

2.1

;:;

0.;

Z.i

3.0

18.9

29.8

19.2

;:2

4.1

2.6

1.2

1.1

1.;

11.7

22.3

19.2

14.4

:::

4.9

7.0

2.2

0.9

4.5

27.3

10.4

17.0

1!::

11.0

5.9

3.7

0.3

0.5

3.9

6.2

17.6

22.4

19.9

16.6

7.1

3.4

1.4

0.6

0.;

0.8

1.7

2.3

1::3

21.7

19.2

11.2

10.7

7.1

1.1

0.;

3.8

7.6

12.6

19.3

20.7

15.4

12.9

3.6

2.6

0.5

0.;

1.2

2.5

8.4

17.6

20.7

21.3

12.3

::$

2.2

0.4

91.5

83.8

75.6

Percentile Skeletal age (hand-wrist) in months —

P,, ------------

P,, ------------

P25

------------

Girls

Below 42--------

42-47-----------

48-53-----------

54-59-----------

6u-65-----------

66-71-----------

72-77-----------

78-83-----------

84-89-----------

90-95-----------

96-101----------

102-107---------

108-113---------

114-119 ---------

120-125---------

81.6

73.8

66.2

85.2

77.7

70.8

98.4

89.9

82.5

105.2

94.7

86.2

107.8

102.0

92.3

112.0

104.8

95.5

115.2

109.4

101.0

117.0

111.3

107.0

122.2

115.5

110.2

126.3 135.2 143.6

118.9 124.3 128.6

114.0 117.2 116.5

Percent distribution of skeletal age—male standaz0.;

0.3

3.0

3.0

1?::

15.5

29.0

19.7

5.9

:::

3.4

1::?

22.8

27.’3

15.8

0.;

2.2

2.7

3.0

3.2

20.0

29.1

15.7

0.4

0.4

;::

11.6

21.6

17.2

0.2

0.4

2.2

6.4

14.8

10.1

0.;

0.3

0.;

1.6

7.8

12.1

1.2

3.0

8.2

13.6

2!::

25.6

15.6

2.0

1.0

2.3

2.;

5.8

13.4

f:.;

17.1

12.0

6.2

3,3

2.6

0.4

O.i

1.;

3.7

12::

19.0

13.5

15.8

14.7

7.6

2.3

0.8

1.Z

2.2

1:::

13.1

15.5

15.0

19.2

7.1

1.9

40
Table 4. Percent distribution for skeletal age (hand-wrist) in months of boys and girls by chronological age

at last birthday in 6-month intervals: United States, 1963-65—COn.

—.—. ——. -..—_- .—_—

Chronological age in months

84- 90- 96- 1o2- 108- 114- 120-

89 95 101 107 113 119 125

Skeletal age

(hand-wrist)

in months 144-

145

2.6

6.;

10.2

4.5

22.0

29.2

9.8

9.6

5.9

;;-

95.9

87.2

79.2

1.6

1.6

1::;

17.9

16.6

15.6

11.4

7.4

;::

126- 1

132- 138-

131 137 143

78-

83

0.3

102.2

93.1

83.6

0.4

0.3

2.0

$;

13:8

19.1

16.2

16.3

13.5

5.5

1.1

0.4

0.3

Girls—Con. Percent distribution of skeletal age-male standard

126-131---------

132-137---------

138-143---------

144-149 ---------

150-155 ---------

156-161---------

162-167 ---------

168-173 ---------

174-179 ---------

180-185---------

186-191---------

192-195---------

0.;

0.3

2.5

:::

0.;

0.2

0.4

7.8

1.3

0.9

1.1

0.5

0.3

11.3

4.9

2.5

2.2

;:+

0.8

0.3

15.6

6.0

7.1

4.0

5.9

3.0

1.8

1.8

16.3

10.0

10.2

1:::

6.7

2.1

0.3

0.5

10.0

12.1

6.8

7.3

1;:?

10.3

4.2

0.8

0.6

6.3

5.2

5.6

1::;

19.7

19.2

;:;

0.7

0.8

2.5

3.3

6.4

1;::

16.9

19.3

16.4

7.6

1.5

2.5

0.8

0.4

0.4

0.;

Percentile

P,, ------------

-.--.-------

p2; ------------

Skeletal age (hand-wrist) in months

108.9 112.2 115.6 120.8 125.1 136.4 147.2 158.4 164.0 169.8 170.2

99.8 106.7 109.8 114.8 118.1 124.7 131.8 143.1 156.7 161.6 162.9

89.2 95.5 102.3 108.8 112.6 116.9 120.7 128.0 145.0 152.1 156.5

Girls

Below 42--------

42-47-----------

48-53 -----------

54-59-----------

60-65-----------

66-71-----------

72-77-----------

78-83-----------

84-89-----------

90-95-----------

%;l:;:---------

---------

108-113---------

114-119---------

120-125---------

126-131---------

132-137---------

138-143 ---------

144-149---------

150-155---------

156-161---------

162-167---------

168-173---------

174-179---------

180-185---------

186-191---------

192-195 ---------

Percentile

;75 ====

P: ------------

Percent distribution of skeletal age—female equivalent

O.z

0.;

1.4

J::

18.2

28.5

10.5

8.5

6.0

1.6

1.3

0.6

0.6

lf:i

13.2

23.0

16.8

15.8

13.2

A:!

0.;

0.;

1.2

5.0

9.5

18.9

14.8

12.6

25.9

8.0

2.7

0.3

0.6

0.2

1.0

2.2

9.6

1!::

33.0

18.7

4.5

:::

0.8

L33.O

128.4

121.0

0.;

2.3

3.3

1::2

27.3

20.3

13.3

6.4

1.8

2.5

0.5

2.6

1:::

31.4

24.3

16.9

5.2

3.2

0.2

1.0

5.2

1:::

13.7

29.8

22.6

5.8

0.9

0.6

0.9

1.2

2.4

3.1

1:::

24.7

26.2

10.8

5.6

2.1

0.2

0.3

0.;

1.Z

:::

5.6

22.0

27.0

22.2

13.1

1.8

1.1

0.9

0.;

2.2

3.6

3.0

11.0

26.1

24.2

17.4

6.3

3.3

1.5

1.1

1.7

5.3

8.2

14.0

15.7

14.1

21.2

15.0

3.2

M

0.2

Skeletal age (hand-wrist) in months

97.2

92.7

82.5

100.6

95,4

88.6

105.8

99.8

94.8

109.1 116.2

103.1 108.8

97.6 101.9

122.6 129.2

113.4 120.0

105.7 111.0

I-37.8 138.2

130.8 131.9

125.1 128.2

82.9 88.6 94.9

74.2 80.1 86.8

65.2 70.4 76.2

I I 1

41
Table 5. Percent of boys and girls showing the number of radio-opaque hand-wrist bones—ossifying and

adult—by chronologicalage in years at last birthday: United States, 1963-65

Stage of

maturation and

number of

hand-wrist bones

Total-------

Children with 1

or more bones

not yet adult--

10 or fewer-------

15 or fewer-------

20 or fewer-------

21 or fewer-------

22 or fewer-------

23 or fewer-------

24 or fewer-------

25 or fewer-------

26 or fewer-------

27 or fewer-------

28 or fewer-------

29 or fewer-------

30 or fewer-------

31 or fewer-------

Children with 1

or more

adult bones---

only 1------------

2 or fewer--------

3 or fewer--------

4 or fewer--------

5 or fewer--------

6 or fewer--------

7 or fewer--------

8 or fewer--------

12 cm fewer-------

15 or fewer-------

16 or fewer-------

1? or fewer-------

23 or fewer-------

28 or fewer-------

Boys—chronological age in years Girls—chronological age in yeara

6 7 8 9 10 11 6 7 8 9 10 11

Percent of children

100.0

100.0

0.1

0.3

0.9

3.0

9.4

27.9

42.7

53.6

79.7

99.6

100.0

100.0

100.4J

100.0

100.0

0.2

0.4

0.5

0.7

3.1

9.6

17.6

26.7

48.5

99.0

Loo.o

100.0

100.0

100.0

100.0

0.2

0.2

0.2

0.4

1.0

2.4

5.3

9.1

24.9

95.4

100.0

100.0

100.O

!00.0

!00.0

0.1

0.5

0.5

0.5

0.8

1.2

1.4

2.6

6.5

83.4

99.4

99.7

.00.0

100.0

100.0

0.2

0.2

0.2

0.2

0.2

0.2

0.6

1.5

61.0

99.4

99.8

100.0

100.0

100.0

0.2

0.2

0.2

0.2

0.2

0.2

0.4

1.1

36.9

89.4

97.4

100.0

100.0

100.0

0.2

0.8

3.0

6.0

10.8

30.4

94.0

99.8

LOO.O

100.0

100.0

100.0

0.1

0.1

0.1

0.1

0.3

1.0

2.2

12.3

81.9

99.8

99.9

100.0

100.0

99.8

0.2

0.2

0.2

0.2

0.2

0.2

0.7

1.5

2.3

3.9

55.1

96.5

98.9

99.8

0.2

0.2

100.0

99.0

0.2

0.2

0.2

0.2

0.2

0.2

0.4

0.4

1.1

2.4

26.6

84.6

95.3

99.0

1.0

0.5

0.5

0.8

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

1.0

100.0

96.7

0.3

0.3

0.3

0.9

1.2

1.7

2.2

3.4

12.8

56.3

83.3

96.7

3.3

1.5

2.1

2.3

2.5

2.7

2.9

3.3

3.3

3.3

3.3

3.3

3.3

3.3

3.3

100.0

88.0

0.2

0.5

1.7

1.7

2.3

2.7

4.6

5.7

7.2

8.4

11.6

30.8

65.1

88.0

12.0

1.5

5.4

6.2

6.8

7.8

8.9

10.1

10.6

11.2

11.4

11.5

11.8

12.0

12.0

43
Table 6.

“an’ ‘tandard‘:v:ation ‘%)’

and standarderror of mean (S~) of bone-specificskeletal ages for the 31 ind~vldualhan -wristbones of boys and girls and number of children,by

chronologicalage in years at last birthday:United States, 1963-65

Hand-wristbone and value

Radius:

mean------------------------------------------

s

s; :::::::::::::::::::::::::::::::::::::::::::

Ulna:

mean------------------------------------------

s -------------------------------------------

s! -------------------------------------------

Capltate:

mea~------------------------------------------

Sx -------------------------------------------

Sz -------------------------------------------

Hamate:

mean------------------------------------------

S* ------------------------------------------

:x -------------------------------------------

Trlquetral:

mean------------------------------------------

Sx -------------------------------------------

% -------------------------------------------

Lunate:

mean------------------------------------------

------------------------------------------

~- -------------------------------------------

Scaphoid:

mean------------------------------------------

Sx --------------------------------------------

~ -------------------------------------------

Trapezium:

mean------------------------------------------

Sx -------------------------------------------

+ ------------------------------------------

Trapezoid:

mean------------------------------------------

Sx -------------------------------------------

----------------------------------------

Me%carpal 1:

mean------------------------------------------

s, -------------------------------------------

-------------------------------------------

Me%carpal II:

mean------------------------------------------

Sx -------------------------------------------

------------------------------------------

Me%carpal III:

mean------------------------------------------

Sx -------------------------------------------

------------------------------------------

Me%carpal IV:

mean------------------------------------------

Sx -------------------------------------------

Sz ------------------------------------------

MetacarpalV:

mean------------------------------------------

Sx -------------------------------------------

Sz ----------------------------.--------------

Proximalphalanx I:

mean------------------------------------------

Sx -------------------------------------------

SE -------------------------------------------

Boys—chronological age in years

I I I I I

617 [819110111

I I I I I

Bone-specificskeletalage in months—male

75.0

13.26

0.66

85.8

9.08

0.73

76.1

12.79

0.55

75.9

12.46

0.54

73.8

17.78

0.86

70.2

17.76

1.02

83.5

11.55

0.60

76.8

11.77

0.57

80.6

10.30

0.47

71.8

14.48

0.60

75.1

14.57

0.69

74.8

14.34

0.71

74.1

14.64

0.65

73.6

14.94

0.65

76.5

12.78

0.55

85.6

12.75

0.53

91.2

10.09

0.53

86.4

12.21

0.57

85.8

11.21

0.47

86.1

15.76

0.57

82.7

18.36

0.81

91.0

12.84

0.63

83.3

13.73

0.77

88.0

11.98

0.56

83.7

14.75

0.74

86.3

13.55

0.62

86.2

13.41

0.62

85.9

13.71

0.62

85.8

14.15

0.71

87.4

12.03

0.56

standard

95.7

12.88

0.56

97.3

10.77

0.45

96.2

12.72

0.50

95.6

12.06

0.51

97.1

14.85

0.51

94.7

18.03

0.62

99.2

13.27

0.52

92.5

15.42

0.69

97.0

13.27

0.59

94.3

14.10

0.62

95.7

13.75

0.51

95.6

13.49

0.46

95.3

1:.;;

.

95.4

13.79

0.51

96.7

12.63

0.53

106.2

12.26

0.48

105.4

11.87

0.42

105.3

12.10

0.49

104.9

11.75

0.45

106.6

11.44

0.35

105.5

15.18

0.60

106.9

12.Uo

0.45

101.8

14.98

0.65

106.2

11.34

0.50

104.3

12.90

0.39

105.4

13.02

0.55

105.2

13.30’

0.59

104.9

13.56

0.58

104.8

13.76

0.57

105.0

13.58

0.67

113.7

11.22

0.53

112.7

11.22

0.42

114.2

11.38

0.56

114.5

11.78

0.59

114.3

10.47

0.50

114.5

12.64

0.50

114.1

1;.();

.

110.0

13.33

0.65

113.1

10.19

0.42

111.9

11.60

0.60

112.7

11.51

0.52

112.4

12.02

0.57

112.1

11.76

0.53

112.2

12.08

0.55

113.2

13.12

0.64

124.2

13.32

0.49

123.4

12.92

0.55

124.6

1$;;

.

125.9

14.34

0.62

124.1

12.89

0.50

125.1

12.96

0.61

124.2

12.43

0.51

121.5

14.44

0.68

123.1

13.49

0.52

123.0

13.95

0.57

122.7

13.44

0.50

123.1

14.05

0.50

122.7

14.15

0.48

123.0

14.56

0.55

124.6

15.63

0.71

44
Table 6. Mean, standarddeviation (Sx), and standarderror of uean (SX) of bone-specificskeletal ages for the 31 individualhand-wrist bones of boys and girls and number of children,by

chronological age in years at last birthday:United States, 1963-65—COn.

Girls—chronologicalage in years

I I I I I

Bone-specificskeletalage in months—male

standard

85.4

13.78

0.57

90.5

;.:;

.

87.9

13.32

0.60

87.4

12.47

0.47

89.5

16.26

0.45

85.0

18.18

0,87

94.4

12.29

0.50

89.2

1.2.67

0,56

90.7

12.09

0.35

90.6

14.07

0.57

89.6

14.56

0.60

89.6

1:.::

.

89.2

1$;;

.

89.1

1:.;!

.

89.9

1:.;5

.

97.2

13.43

0.55

98.4

11.43

0.61

99.6

13.16

0.56

99.5

13.03

0.57

102.0

13.44

0.64

97.5

16.49

0.76

103.3

11.71

0.50

99.5

13.30

0.64

102.0

11.99

0.54

101.7

12.84

0.53

101.7

13.99

0.66

101.7

1.3.88

0.63

101.2

1;.:$

.

100.9

1:.;;

.

100.8

14.10

0.54

108.2

13.12

Q.4Q

107.2

12.55

0.52

110.1

12.42

0.53

110.2

12.55

0.59

111.1

10.70

0.45

109.1

15.42

0.60

111.7

9.92

0.34

109.2

11.48

0.50

110.4

10.78

0.48

111.0

12.70

0.43

110.8

13.04

0.46

110.8.

13.29

0.48

110.4

1;.:;

.

110.4

1$.;;

.

112.8

1:.:;

.

119.1

15.68

0.63

119.1

13.92

0.69

120.9

15.56

0.75

122.5

15.56

0.76

121.1

13.98

0.58

120.3

14.67

0.63

120.9

12.54

0.58

119.0

13.01

0.61

120.1

12.69

0.70

122.3

16.34

0.75

121.6

15.93

0.66

121.8

16.36

0.74

121.7

16.49

0.74

122.2

17.05

0.73

126.4

18.88

0.85

134.3

18.72

0.78

133.1

16.20

0.72

136.4

18.58

0.89

138.4

17.36

0.72

134.0

16.77

0.59

133.7

17.29

0.63

133.3

15.32

0.54

133.2

17.05

0.74

133.3

16.70

0.65

137.1

1:.:;

.

;;6;;

0:71

136.8

18.46

0.70

136.6

18.68

0.72

133.1

19.01

0.74

141.9

1:.;;

.

154.2

16.11

0.58

151.7

15.90

0.56

154.5

16.18

0.72

155.2

13.97

0.59

150.5

15.85

0.59

150.8

16.43

0.66

150.3

15.53

0.64

151.8

15.84

0.65

150.9

15.40

0.71

155.3

15.97

0.72

154.2

16.62

0.67

155.1

16.36

0.66

155.1

16.39

0.69

156.4

16.17

0.65

160.5

1;.;;

.

Girls—chronologicalage in years

I I I I I

I i I I I

Bone-specificskeletalage in months—female

77.6

12.52

0.52

86.8

;.:;

.

75.9

11.50

0.52

75.4

10.76

0.41

76.5

1;.;:

.

70.0

14.97

0.72

77.4

10.08

0.41

82.6

11.73

0.52

77.7

10.36

0.30

75.6

1;.;;

.

74.6

12.12

0.50

74.8

12.14

0.53

74.2

11.95

0.49

74.1

12.56

0.52

74.9

1;.;;

.

88.3

12.20

0.50

87.9

10.21

0.54

86.6

11.44

0.49

85.8

11.28

0.49

88.0

11.60

0.55

85.8

1$:;

.

86.4

9.79

0.42

86.8

1;.;:

.

90.0

10.58

0.48

86.7

10.95

0.45

86.7

11.93

0.56

87.7

11.97

0.54

86.2

11.79

0.54

85.9

11.94

0.50

85.8

12.00

0.46

equival~nt

95.1

11.53

0.35

93.2

10.91

0.45

96.0

10.83

0.46

96.2

10.96

0.51

96.1

9.26

0.39

98.4

13.91

0.54

96.7

8.59

0.29

95.2

10.01

0.44

95.7

:.;;

.

97.0

11.10

0.38

95.8

11.27

0.40

96.8

11.61

0.42

95.4

11.67

0.42

95.4

12.12

0.48

98.8

13.95

0.57

104.1

13.71

0.55

104.1

12.17

0.60

105.9

13.63

0.66

107.2

13.62

0.67

10.5.6

12.19

0.51

105.3

12.84

0.55

105.4

10.93

0.51

104.0

11.37

0.53

105.1

11.10

0.61

107.2

1$:;

.

106.6

13.96

0.59

106.8

14.35

0.65

136.7

1$::

.

106.6

14.87

0.64

109.7

16.39

0.74

115.2

16.06

0.67

113.6

13.83

0.61

116.4

15.86

0.76

117.4

14.73

0.61

115.0

14.39

0.51

;:4;;

0:54

113.6

13.06

0.46

114.1

1:.:;

.

114.3

1$:;

.

116.6

15.58

0.57

116.0

15.57

0.61

116.4

1:.:;

.

116.3

15.90

0.61

117.1

16.12

0.63

119.4

15.71

0.66

127.2

13.29

0.48

125.7

1;.:;

.

127.5

13.35

0.59

128.1

11.53

0.49

124.8

13.14

0.49

124.9

1;.;;

.

124.6

12.87

0.53

125.4

13.09

0.54

124.9

13.57

0.59

128.2

13.18

0.59

127.6

13.75

0.55

128.0

13.50

0.54

128.0

13.53

0.57

128.7

13.31

0.53

130.8

12.89

0.61

45
Table 6. Mean, standarddeviation (S ), and standarderror of mean (sy) of bone-speciftcskeletal ages for the 31 individualban%-wristbones of boys and girls and number of children,by

chronologicalage in years at last birthday:United States, 1963-65—Con.

Hand-wristbone and value

Proximaluhalanx II:

mean------------------------------------------

s, ------------------------------------------

s? -------------------------------------------

Proximalphalanx III:

mean------------------------------------------

------------------------------------------

:; -------------------------------------------

Proximalphalanx IV:

mean--------------------------- -----------------

s, -------------------------------------------

-------------------------------------------

Pr%imal phalanxV:

mean------------------------------------------

s, -------------------------------------------

-------------------------------------------

Mi~%le phalanx II:

mean------------------------------------------

s~ ------------------------------------------

-------------------------------------------

Mi;%le phalanx 111:

mean------------------------------------------

Sx -------------------------------------------

-------------------------------------------

Hi%le phalanx IV:

mean------------------------------------------

S* -------------------------------------------

SE -------------------------------------------

Middle phalanxV:

mean------------------------------------------

Sx -------------------------------------------

s: -----------------------------------------

Distal phalanx I:

mean------------------------------------------

Sx ------------------------------------------.

SE -------------------------------------------

Distal phalanx 11:

mean------------------------------------------

-------------------------------------------

% -------------------------------------------

Distal phalanx 111:

mean------------------------------------------

s. ------------------c------------------------

SF -------------------------------------------

Distal phalanx IV:

mea>------------------------------------------

q -------------------------------------------

SE -------------------------------------------

Distal phalanx V:

mean------.-----------------------------------

q -------------------------------------------

s~ -------------------------------------------

Pisiform:

mean------------------------------------------

Sx -----------------------------------------

s~ -------------------------------------------

Abductor sesamoid:

mean------------------------------------------

Sx -------------------------------------------

s~ -------------------------------------------

Flexor sesamoid:

mean-----------------------------------------

Sx -------------------------------------------

SE -------------------------------------------

BoysAhronological age in years

6

I

7

I

8

I

9

I

10 I11

Bone-svecificskeletal age in mo%ths-male

standard

78.8

12.39

0.55

78.1

12.24

0.56

77.2

12.66

0.58

77.8

13.03

0.58

80.8

12.25

0.47

79.1

12.57

0.48

79.6

12.92

0.50

78.9

14.00

0.51

74.2

14.08

0.58

77.0

12.65

0.56

76.3

13.08

0.53

75.8

13.56

0.58

76.2

13.34

0.58

*

*

89.8

12.86

0.57

89.1

13.18

0.54

88.9

13.41

0.55

89.5

13.32

0.57

91.3

12.57

0.62

89.7

12.64

0.59

90.6

12.93

0.64

90.2

13.93

0.70

87.1

14.48

0.63

89.7

13.50

0.74

89.4

14.02

0.80

89.3

14.31

0.78

89.1

14.18

0.75

112.7

2.10

1.65

98.9

12.48

0.48

98.5

12.92

0.50

98.5

12.94

0.53

99.1

12.79

0.52

100.3

12.55

0.54

99.2

12.80

0.51

99.7

12.61

0.56

99.8

13.52

0.56

99.1

13.79

0.64

100.5

12.99

0.54

100.2

1:.;:

.

100.2

13.37

0.55

99.9

13.38

0.55

115.4

13.12

1.11

106.8

12.56

0.47

106.6

12.92

0.50

106.7

13.23

0.53

106.9

13.12

0.52

108.2

12.70

0.55

107.5

12.97

0.53

107.4

12.46

0.52

107.7

12.85

0.55

107.6

12.73

0.52

108.3

11.18

0.40

108.2

11.48

0.39

108.3

11.83

0.44

108.2

12.00

0.48

117.5

7.53

0.84

*

*

*

*

*

*

114.2

11.41

0.51

114.3

11.79

0.52

115.0

12.07

0.48

115.0

11.76

0.45

115.5

11.96

0.43

115.0

12.14

0.47

114.5

11.60

0.47

114.8

12.09

0.46

114.8

11.88

0.57

115.2

10.35

0.47

115.3

10.22

0.48

115.2

10.34

0.48

115.1

10.59

0.50

119.0

8.24

0.57

*

*

*

*

*

*

125.1

14.50

0.63

125.1

14.64

0.66

125.7

14.62

0.65

125.9

14.44

0.61

126.7

14.16

0.56

126.4

14.32

0.59

125.4

13.95

0.60

126.0

14.38

0.63

125.8

1:.;;

.

125.3

14.12

0.60

125.4

14.16

0.61

125.6

14.34

0.62

125.9

14.51

0.62

126.8

13.69

0.67

15.66

5.87

0.78

161.0

6.11

1.04

A6
Table 6. Mean, standard deviation (Sx),

of boys and girls a% number of children, by

and standard error of mean ( -) of bone-specific skeletal ages for the 31 individual hand-wrist bones

chronological age in years at last birthday: United States, 1963-65—Con.

Girls—chronological age in years

6 7 8 9 10 11

Bone-specific skeletal

92.4

14.70

0.64

91.9

14.97

0.65

91.7

1:.;;

.

92.2

15.02

0.69

93.7

1$;;

.

92.4

14.36

0.64

93.0

14.42

0.63

93.3

1;.;5

●

91.0

1!$:;

.

93,5

13.88

0.61

93.0

14.19

0.65

92.9

14.44

0.70

92.9

14.20

0.64

116.6

;.:;

.

*

*

*

103.4

13.48

0.48

103,0

13.85

0.51

103.1

1;.;;

.

103.2

13.89

0.46

103.5

13.43

0.40

102.6

13,94

0.39

102.8

13.49

0.42

102.9

13.97

0.43

102.1

13.96

0.52

104.0

12.33

0.40

103.7

12.83

0.45

103.7

1;.;;

.

103.5

13.03

0.51

117.0

6.36

0.72

*

*

*

it

*

*

stan<

113.8

1$.:;

.

113.7

14.25

0.64

114.0

14.69

0.73

114.4

1.4.61

0.70

114.4

14.22

0.60

113.5

14.52

0.68

113.1

13.87

0.66

113.4

14.00

0.62

113.0

14.15

0.54

112.9

1$:;

.

112.7

12.29

0.51

112.7

12.42

0.51

112.5

12.32

0.53

120.1

8.63

0.53

154.6

6.93

1.94

*

*

*

age in months-male

rd

125.8

17.60

0.81

125.8

17.85

0.82

126.1

17.61

0.80

126.4

17.55

0.82

126.4

16.90

0.70

125.9

17.29

0.76

125.1

16.96

0.72

125.5

17.39

0.72

125.0

17.88

0.81

124.0

16.07

0.70

124.0

16.24

0.73

124.0

16.44

0.73

123.9

16.79

0.74

126.1

12.40

0.64

156.8

6.42

0.64

161.3

7.10

0.70

141.7

1:.::

.

141.9

18.80

0.80

142.0

18.37

0.75

142.2

18.19

0.76

141.7

18.19

0.81

141.4

18.49

0.80

140.3

18.62

0.83

140.8

18.97

0.89

139.9

19.21

0.84

138.1

18.47

0.80

138.5

18.64

0.78

138.8

18.81

0.78

138.9

19.06

0.80

138.4

15.99

0.68

158.5

6.73

0.38

162.4

7.38

0.51

160.4

15.74

0.71

160.6

16.01

0.70

160.8

16.15

0.75

160.9

15.82

0.71

160.2

15.91

0.7s

160.2

16.30

0.73

159.6

16.87

0.77

160.2

16.55

0.76

158.7

15.14

0.64

157.1

16.23

0.76

157.4

15.96

0.72

157.8

16.22

0.74

158.2

16.16

0.71

153.9

15.90

0.72

162.9

8.21

0.30

165.9

8.65

0.44

Girls—chronological age in years

6 7 8 9 10 11

Bone-specific skeletal age in months—female

equivalent

77.4

12.31

0.54

76.9

12.53

0.54

76.7

12.63

0.56

77.2

12.58

0.58

78.7

11.86

0.56

77.7

12.08

0.54

78.0

12.09

0.53

74.6

11.59

0.53

75.0

12.63

0.54

78.5

11.65

0.51

79.0

12.05

0.55

78.9

12.26

0.59

77.9

11.91

0.54

102.8

6.06

1.58

*

*

*

88.4

11.52

0.41

88.0

11.83

0.44

88.1

12.08

0.42

88.2

11.87

0.39

89.5

11.61

0.35

88.6

12.04

0.34

88.8

Il.65

0.36

88.8

12.06

0.37

87.1

1:.:;

.

89.0

10.55

0.34

90.0

11.14

0.39

90.0

11.21

0.41

88.5

11.14

0.44

103.0

5.60

0.63

*

*

*

*

*

*

98.8

12.26

0.52

98.7

12.37

0.56

99.0

12.76

0.63

100.4

12.82

0.61

100.1

12.44

0.52

98.8

12.64

0.59

98.2

12.04

0.57

98.4

12.15

0.54

98.0

12.27

0.47

97.9

10.27

0.42

98.7

10.76

0.45

93.7

10.88

0.45

97.5

10.68

0.46

105.1

7.55

0.46

127.6

5.72

1.60

*

*

*

108.8

15.22

0.70

109.4

15.52

0.71

109.6

15.31

0.70

109.7

15.23

0.71

109.7

14.67

0.61

109.4

15.02

0.66

109.0

14.78

0.63

108.5

15.03

0.62

108.0

15.45

0.70

108.0

14.00

0.61

108.0

14.14

0.64

108.0

14.32

0.64

107.9

1$:5

.

110.0

U_&

.

128.9

5.28

0.53

131.6

5.79

0.57

119.7

15.54

0.70

119.4

15.82

0.67

119.5

15.46

0.63

119.6

15.30

0.64

119.4

15.33

0.68

119.2

15.59

0.67

118.6

15.74

0.70

118.8

16.01

0.75

117.9

16.19

0.71

117.1

15.66

0.68

117.5

15.81

0.66

U7.8

15.96

0.66

117.9

16.18

0.68

117.4

13,56

0.58

1;05;

0:31

132.4

6.02

0.42

130.7

12.83

0.58

132.6

13.22

0.58

132.8

1;.;3

.

131.4

12.92

0.58

131.1

13.02

0.61

131.1

13.34

0.60

130.8

13.83

0.63

130.7

13.50

0.62

130.4

12.44

0.53

129.1

13.34

0.62

129.4

1:.;;

.

129.8

13.34

0.61

130.2

1:.;;

.

126.9

13.11

0.59

132.9

6.7’0

0.24

134.4

7.01

0.36

47
Table 6. Mean, standarddeviation (S ), and standarderror of mean (Si) of bone-spec~ficskeletal ages for the 3L individualban%-wristbones of boys and girls and number of children,by

chronologicalage in years at last birthday:United States, 1963-65—Con.

Hand-wristbone

Radius------------------------------------------

Ulna---------------------------------------------

Cavitate----------------------------------------

Hamate------------------------------------------

Triquetral--------------------------------------

Lunate------------------------------------------

Scaphoid----------------------------------------

Trapezium---------------------------------------

Trapezoid---------------------------------------

Metacarpal 1------------------------------------

MetacarpalII-----------------------------------

MetacarpalIII----------------------------------

Metacarpal IV-----------------------------------

MetacarpalV------------------------------------

Proximalphalanx I------------------------------

Proximalphalanx II-----------------------------

Proximalphalanx III----------------------------

Proximalphalanx IV-----------------------------

Proximalphalanx V------------------------------

Middle phalanx

Middle phalanx

Middle phalanx

Middle phalanx

Distal phalanx

Distal phalanx

Distal phalanx

Distal phalanx

Distal phalanx

II-------------------------------

III------------------------------

Iv-------------------------------

v -----------------.---------------

1--------------------------------

11-------------------------------

111------------------------------

Iv-------------------------------

v------.--------------------------

Pisiform----------------------------------------

Adductor sesamoid-------------------------------

Flexor sesamoid---------------------------------

Boys—chronological age in years

6 7 8

I

9 10 11

Number of children in thousands

1,999

562

1,999

1,999

1,936

1,792

1,166

1,079

1,187

1,995

1,999

1,999

1,999

1,999

1,996

2,002

2,002

2,002

2,002

2,002

1,998

1,998

1,992

1,996

1,993

1,989

1,989

1,989

7

2,007

1,232

2,007

2,007

1,996

1,924

1,645

1,510

1,671

2,004

2,007

2,007

2,007

2,007

2,006

2,008

2,008

2,008

2,008

2,003

2,003

2,003

1,999

1,996

2,001

2,001

2,001

1,997

23

1,968

1,681

1,965

1,965

1,964

1,940

1,821

1,751

1,880

1,965

1,968

1,968

1,968

1,968

1,961

1,964

1,964

1,964

1,964

1,964

1,964

1,964

1,939

1,958

1,961

1,961

1,961

1,961

91

1,937

1,871

1,942

1,942

1,938

1,932

1,927

1,896

1,925

1,942

1,942

1,942

1,942

1,942

1,940

1,940

1,944

1,944

1,944

1,934

1,931

1,937

1,933

1,936

1,931

1,934

1,937

1,937

329

11

6

1,935

1,932

1,935

1,935

1,931

1,931

1,931

1,919

1,935

1,935

1,932

1,935

1,935

1,935

1,935

1,935

1,935

1,935

1,935

1,931

1,931

1,931

1,931

1,931

1,931

1,931

1,931

1,931

749

15

2

1,903

1,903

1,903

1,903

1,903

1,903

1,903

1,899

1,899

1,903

1,906

1,906

1,906

1,906

1,906

1,906

1,906

1,906

1,906

1,906

1,906

1,906

1,897

1,906

1,906

1,903

1,903

1,906

1,176

228

52

48
Table 6.

‘can’ ‘=andarG‘:v:a’ion ‘%)’

and standarderror of mean (SX) of bone-specificskeletal ages for the 31 mdlvldual han -wristbones Of boys and girls and number of children,by

chronologicalage in years at last birthday:United States, 1963-65—Con.

Girls-chronologicalage in years I

Girls—chronologicalage in years

6 7 8 9 10 11 6 7 8 9 10 11

Number of children in thousands

1>962

1,419

1,962

1,962

1,955

1,927

1,830

1,809

1,869

1,962

1,962

1,962

1,962

1,957

1,962

1,962

1)962

1,958

1,962

1,962

1,962

1,958

1,949

1,956

1,957

1,957

1,954

1,962

120

3

1,986

1,796

1,986

1,986

1,986

1,932

l,9&j

1,957

1,969

1,986

1,983

1,983

1,983

1,983

1,986

1,984

1,984

1,986

1,986

1,980

1,984

1,984

1,976

1,976

1,977

1,980

1,984

1,977

370

4

2

1,918

1,883

1,918

1,914

1,908

1,911

1,903

1,903

1,914

1,914

1,914

1,914

1,914

1,914

1,908

1,914

1,914

1,914

1,914

1,902

1,914

1,914

1,908

1,896

1,897

1,902

1,904

1,905

862

67

16

1,885

1,878

1,881

1,881

1,860

L,871

1,885

1,873

1,876

1,881

1,881

1,881

1,881

1,881

1,881

1,881

1,881

1,881

1,881

1,878

1,881

1,881

1,863

1,871

1,875

1,878

1,878

1,872

1,382

316

89

1,872

1,870

1,840

1,845

1,823

1,827

1,856

1,844

1,842

1,870

1,872

1,872

1,872

1,872

1,870

1,869

1,869

1,869

1,869

1,866

1,866

1,866

1,856

1,859

1,862

1,864

1,866

1,861

1,618

872

290

1,844

1,844

1,744

1,777

1,641

1,769

1,784

1,730

1,730

1,828

1,834

1,834

1,834

1,834

1,828

1,835

1,835

1,823

1,820

1,835

1,842

1,842

1,822

1,752

1,767

1,760

1,769

1,769

1,568

1,516

648

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

J..

.

.

.

. . .

.,.

. . .

. . .

. . .

,..

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

49
Table 7. Mean and standard deviation (Sx) of bone-specifLc skeletal ages for selected

hand-wrist bones of boys andgirls,by chronological age in 6-month intervals: United

States, 1963-65

Sex and chronological age

Boys-male standard

6

7

8

9

years:

O-5 months -------------------

6-11 months ------------------

years:

O-5 months -------------------

6-11 months ------------------

years:

O-5 months -------------------

6-11 months ------------------

years:

O-5 months -------------------

6-11 months ------------------

10 years:

O-5 months -------------------

6-13 months ------------------

11 years:

O-5 months -------------------

6-11 months ------------------

12 vears:

6

7

8

9

0~1 month --------------------

Girls—female equivalent

yeara:

O-5 months -------------------

6-11 months ------------------

years:

O-5 months -------------------

6-11 months ------------------

years:

O-5 months -------------------

6-11 months ------------------

vears:

0-5 months -------------------

6-11 months ------------------

10 years:

O-5 months -------------------

6-11 months ------------------

11 years:

O-5 months -------------------

6-11 months ------------------

12 years:

O-1 month ---------------------

Radius Ulna Scaphoid

Mean

I

‘x I

Mean

I

Sx

I

Mean I

Sx

72.4

77.6

82.5

88.6

92.7

98.3

104,5

107*7

111.6

115 ● 9

121.0

126.8

130,3

76.0

79.6

86.0

91.2

93.6

96.3

100,2

107.4

111,8

118.2

124.9

128.8

132.4

Bone-specific skeletal age in months

13.34

12.62

11.91

12.83

13.09

12.08

12.69

11.66

11.07

10.96

11.80

13.72

15.20

12..60

13.12

12.78

10.97

12.23

10.09

11.93

14.42

14.67

16.24

12.98

13.61

7.88

84.8

86.6

88.9

93.0

94.3

99.7

102.7

107.6

110.4

115.1

119.8

126.1

131.5

86.0

87.1

;;.;

.

91.6

94.9

99.8

107.5

110.8

116.6

123.6

127.3

128.4

9.79

8.47

9.40

10.60

10.89

10.66

12.38

11.40

11.21

11.24

11.97

13.59

14.74

8.21

9.69

9.99

10.41

11.17

10.65

11.47

12.76

13.46

14.22

12.67

13.84

11.84

82.5

84.4

88.3

93.4

96.4

101.5

104.9

108.6

112.2

116.1

120.7

126.8

131.9

;;.;

.

83.6

90.4

95.4

98.6

102.9

108.6

;;;.:

●

122.9

125.6

127.7

12.14

11.02

;;.:3

.

13.57

13.01

12.88

11.18

11.10

10.93

11.58

13,02

14.52

10.01

10.13

10.52

9.12

8.62

8.61

9.94

11.97

::.;2

●

;;.:3

.

10.70

50
Table 7. Mean and standard deviation (SX) of bone-specificskeletal ages for selected

hand-wristbones of boys and girls,by chronologicalage in 6-month intervals:United

States, 1963-65—Con.

Metacarpal I Proximal phalanx II Middle phalanx II Distal phalanx II

Mean Sx

;5.;

.

80.6

86.7

91.0

97.3

101.4

106.8

109.6

114.2

119.4

125.9

129.8

73,0

77.8

83.7

90.6

95.1

99.5

103.0

110.0

113.8

120.3

126.5

129.8

130.6

14.43

14.15

13.34

15.43

13.98

13.54

13.46

11.82

11.49

11.23

12.22

14.41

15.77

11.41

11.70

1;.;;

.

11.54

10.04

12.91

14● 41

14.13

16.08

13.42

12.87

10.45

Mean Sx

I

I I

Mean Sx Mean Sx

Bone-specificskeletal age in months

76.9

80.7

87.2

92.3

96.4

101.1

103.8

109.5

112.0

116.5

121.3

128.2

131.5

74.8

79.8

86.2

90.7

95.5

101.6

105.7

112.4

116.8

121.9

129.2

131.9

134.2

12.38

12.09

12.44

12.75

12.80

11.76

12.69

11.81

11.06

11.31

12.34

15.16

17.30

11.94

12.31

12,09

10.58

12.19

11.49

14.04

15.32

14.49

15.73

12.77

12.63

11.19

78.8

83.0

88.6

93.9

97.6

102.7

105.3

110.8

112.7

118.2

123.3

129.5

133.1

77.4

80.4

87.2

91.4

96.6

102.3

106.9

113.4

116.8

122.0

128.8

131.9

134.9

12.13

12.00

12.11

12.44

12.82

11.79

12.07

12.69

11.45

11.83

13.08

14.15

15.76

11.60

11.98

12.24

10.54

12.48

11.69

13.51

14.78

14.27

15.55

12.59

12.84

11.83

74.9

79.2

86.4

92.9

97.8

102.9

106.0

110.3

113.2

117.2

121.9

128.1

130.9

76.1

80.6

86.7

91.3

95.1

100.7

105.2

110.5

115.0

120.5

127.9

130.4

132.4

12.19

12.74

12.99

13.19

13.67

11.84

11.34

10.66

9.86

10.42

12.36

14.72

16.01

11.52

11.47

11.32

9.30

10.50

9.41

12.42

14.67

14.42

16.22

13.53

13.02

11.95

51
Table 8. Selected percentiles in the distribution of bone-specific skeletal ages for each of the

31 hand-wrist bones of boys and girls, by chronological age in years at last birthday: United

States, 1963-65

Hand-wrist bone and percentile

Radius:

P -------- -------- ---------------- -----

P:-------------------------------------

P25-------------------------------------

Ulna:

575-------------------------------------

-------------------------------------

UP;-------------------------------------

Ca xtate:

l+-----------------------------------

-------------------------------------

~af:;:------------------------------------

P,5-------------------------------------

P~--------------------------------------

P25-------------------------------------

Triquetral:

P,,-------------------------------------

$50-------------------------------------

-----------------------------------.-

Lun;;e:

-------------------------------------

$:---------------------------.”--------- p25-------------------------------------

Scaphoid:

-------------------------------------

$:-------------------------------------

p25-------------------------------------

!Prapezium:

P75----------------- -------- -----.-- ----

$50-------------------------------------

-------- -------- ---------------- -----

Tra2~zoid:

#’,,-------------------------------------

Pm -------- --------- ---------------- ---QP,, ------------------------ -------- -----

Metacarpal 1:

P,,-------------------------------------

$50-------------------------------------

-------- -------- -------- -------- -----

Me~2~arpal II:

-------------------------------------

Pa------------------------------------- p25-------------------------------------

Metacarpal 111:

5

75

-------- -------- -------- -------- --.--

.------- ---------------- -------- -----

~e:;;;;ii-=-----------------------------

P,, -------- :----------------------------

$W-------------------------------------

-------- -------- -------- -------------

Met$;arpal V:

P,5-------------------------------------

-------- -------- -------- -------------

f;;;----------------------------------

Pf

:

------- ------- -------------- ------- .-

UP:-------------------------------------

P 25

---------------- ------- --------------

Boys -chronological age in years

I I I I I

6 7 8 9 ‘lo 11

Bone-specific skeletal age in months-male

83.7

75.3

68.4

89.6

85.2

80.4

84.7

78.1

69.8

84.3

78.4

68.9

86.3

77.3

63.4

84.8

70.8

54.9

92.5

82.4

73.5

85.7

76.6

68.9

88.9

78.8

72.3

81.9

72.2

63.7

84.8

78.1

66.1

84.8

77.9

66.0

84.6

76.7

64.2

;3.;

62:8

134.8

134.1

115.6

94.4

85.3

77.8

98.8

90.7

84.2

;3.;

79:3

92.9

86.0

79.2

95.5

87.4

78.1

96.5

85.8

70.6

102.5

91.4

80.3

92.8

;$:

.

94.8

87.6

78.9

93.1

84.0

73.7

94.1

86.9

78.4

93.8

86.9

78.5

92.9

86.9

78.6

94.1

86.6

76.9

116.5

111.8

110.9

standard

106.0

95.0

89.2

106.8

97.3

88.0

108.3

:3.;

.

105.8

94.1

88.3

110.2

99.2

88.4

110.2

98.4

83.6

110.8

102.7

90.3

108.2

:3.:

.

110.3

96.7

88.6

107.0

94.3

86.3

109.7

94.6

87.0

108.9

$&;

.

108.8

94.3

86.7

1;:.;

86:4

118.8

116.1

112.3

115.2

108.8

98.3

114.7

107.0

96.9

114.0

108.4

96.5

114.1

106.5

94.9

113.7

110.3

101.1

116.6

110.4

98.4

114.6

110.8

101.6

113.4

106.7

92.1

114.3

110.6

96.7

112.8

1;;.:

.

114.5

110.1

94.9

114.0

109.6

94.7

113.8

109.2

94.3

113.8

108.8

94.6

120.3

116.2

113.1

12001

114.8

108.1

118.6

114.7

106.9

120.6

114.1

108.9

120.5

114.8

108.4

119.8

114.2

110.2

u;. ;

110:6

120.7

114.5

110.4

117.7

112.9

105.6

118.1

113.9

110.3

117.9

112.6

106.6

118.4

113.8

110.1

118.1

:;:.:

.

117.9

113.6

108.6

117.8“

:;;.;

.

122.8

117.7

113.7

130.6

122.9

116.1

132.4

120.0

115.6

130.7

122.2

115.5

136.2

121.1

115.5

;;:.;

115:2

130.6

122.5

116.9

129.9

122.2

115.5

128.7

118.6

114.1

130.3

118.6

114.7

130.0

119.0

114.5

129.0

118.9

114.7

130.0

119.0

114.7

128.9

118.8

114.4

130.2

118.7

114,2

132.9

123.0

116.6

52
Table 8. Selected”percentiles in the distribution of bone-specific skeletal ages for each of the

31 hand-wrist bones of boys and girls, by chronological age in years at last birthday: United

States, 1963-65-Con.

Girls—chronological age in years

6 7 8 9 10 11

Bone-specific skeletal age in months—male

standard

94.6

;:.;

.

;:.;

84:6

94.9

87.6

80.0

94.4

87.6

80.1

103.1

89.6

80.4

96.7

87.1

75.2

1::.:

85:1

98.7

87.5

82.0

98.8

90.8

81.7

102.1

89.4

80.7

98.1

88.8

80.8

96.9

89.0

80,7

96.8

88.5

80.8

96,9

89.0

80.2

120.2

115.0

111.0

108.3

96.7

89.2

108.0

98.7

88.5

112.2

98.7

90.3

112.5

98.7

90.1

112.7

137.7

92.7

112.5

100.3

86.7

112.8

1;().:

.

112.0

102.8

89.0

112.7

105.3

93.0

112.4

106.3

92.0

113.2

108.1

90.4

113.3

108.0

90.4

112.8

106.7

90,2

112.6

106.2

90.2

120.3

116.1

113.0

116.2

111.5

100.8

115.6

108.5

98.5

116.7

112.4

104.7

117.2

112.9

103.0

116.7

112.9

108.8

118.5

114.9

104.3

117.8

113.3

109.2

116.2

u:. ;

.

116.6

113.2

106.5

117.2

112.5

105.8

117.2

113.1

108.0

117.4

112.8

107.8

117.0

112.7

105.5

117.3

112.5

105.5

124.7

118.4

114.8

125.9

n;. :

.

125.5

117.5

112.1

126.8

118.4

112.9

129.6

118.8

114.0

126.9

118.8

113.5

126.9

119.6

115.4

126.5

119.2

114.3

123.3

116.8

113.4

124.5

117.6

114.1

128.7

118.8

113.8

127.7

118.7

114.2

128.2

118.8

114.2

127.6

118.6

113.7

128.7

118.8

113.4

132.5

123.4

117.3

151.3

130.7

118.7

148.1

132.4

118.5

156.1

132.9

122.0

154.7

140.2

122.4

148.7

132.2

121.1

152.1

129.4

120.4

:;:.;

121:4

150.3

128.9

118.4

150.3

129.6

118.1

154.3

132.9

123.7

152.8

130.8

122.0

153.2

132.6

121.8

154.1

132.4

121.2

156.4

135.8

122.8

153.0

136.5

124.9

164.5

156.7

148.4

163.0

152.9

142.8

164.9

159.4

148.8

163.9

157.9

152.3

164.9

152.6

142.1

162.7

154.9

140.5

161.6

152.9

140.6

164.4

156.7

141.5

164.2

154.2

140.8

168.4

158.8

147.7

166.2

:::.:

.

166.$3

158.8

148.1

166.9

159.4

148.3

168.1

160.6

149.0

:;:.;

144:6

Girls-chronological age in years

6

I

7

I

8

I

9

I

10 I

11

Bone-specific skeletal age in months-female

86.6

78.6

70.0

87.6

;;.:

.

82.9

75.6

68.0

81.6

75.6

67.2

89.1

76.6

68.4

84.7

72.1

64.1

88.1

77.3

68.2

86.4

81.5

71.0

87.7

77.8

68.7

;3.;

65:7

84.6

73.8

65.8

82.8

74.5

65.7

82.7

73.5

65.8

82.9

74.0

65.2

105.2

102.0

99.0

95.2

87.8

81.2

94.0

87.9

84.8

97.3

85.7

78.3

97.8

85.4

78.1

97.7

93.7

79.7

99.2

90.4

71.7

97.8

94.4

77.4

97.5

89.8

82.5

97.7

91.6

81.0

98.4

92.3

77.0

98.2

93.6

75.4

99.3

;;.;

.

97.8

91.8

75.2

97.6

91.2

75.2

105.3

102.6

100.5

equivalent

101.2

96.5

91.4

99.9

94.2

98.9

102.4

97.6

90.7

102.2

97.9

89.0

101.7

97.9

94.4

10305

99.3

97.1

102.8

98.3

95.1

101.2

98.6

90.8

101.6

98.2

92.5

102.2

98.5

91.8

102.2

98.1

93.5

103.4

98.8

93.8

102.0

97.7

91.2

102.3

97.5

90.5

108.7

104.2

101.8

109.4

102.0

97.5

108.8

102.5

97.1

109.9

103.4

98.4

111.8

103.8

99.0

109.9

103.8

98.5

110.3

104.6

100.4

no. 2

103.6

99.3

107.3

101.8

99.2

109.5

102.6

99.1

110.8

103.8

99.4

110.7

103.7

99.2

111.2

104.4

100.2

110.6

103.6

98.7

110.8

103.8

93.4

113.8

107.7

103.3

125.3

112.7

103.7

123.1

113.2

103.5

128.6

113.9

107.0

;:;.;

107:2

123.7

IL;.:

.

126.0

112.2

105.4

124.6

111.8

106.2

124.6

111.4

103.4

124.6

112.3

103.1

127.6

113.9

107.8

126.8

112.9

107.0

127.1

113.8

106.8

127.6

113.7

106.2

128.4

115.4

106.9

126.5

116.2

108.9

134.2

128.8

123.7

132.5

126.9

119.8

134.4

131.2

123.9

133.9

129.9

126.2

134.4

125.8

119.6

132.7

127.9

118.8

131.8

125.9

119.2

-133.7

128.8

119.2

133.6

127.6

118.8

136.7

130.4

122.8

135.2

130.1

122.3

135.4

130.4

123.6

135.9

130.7

123.3

136.1

131.8

124.0

136.7

130.4

121.3

53
Table 8. Selected percentiles in the distribution of bone-specific skeletal ages for each of the

31 hand-wrist bones of bovs and girls. bv chronological age in Years at last birthday: United

States, 1963-55-Con. “ - - “

Hand-wrist bone and percentile

Aclductorsesamoid:

$: -------------------------------------

-------------------------------------

Pa:;-;;;;:;:;--------------------------

$,5-------------------------------------

-------------------------------------

P; -------- -------- -------- -------- -----

Pro:<mal phalanx”I:

------------------------.------------

$: -------------------------------------

-------------------------------------

Proximal phalanx II:

P -------- ---------------- -------- -----

Pfi -------- -------- -------- -------- -----

P25-------------------------------------

Proximal phalaox 111:

P 75-------- -------- -------- -------- -----

-------- -------- -------- -------- ----

$;: -----” --------------------- --------- -

Prox mal phalanx IV:

P 75 ------------------- ---------- ---------- -

$

-------. -------- --------- -------- -----

--------------------------- --------. .

ProxEal phalanx V:

----------------------------“--------

5: -------------------------------------

P~ ------------------ -------------------

Middle phalanx II:

f

75

---------------------------- --------- -

--------- ------------------ --------- -

P: -------- ---------------- -------- -----

Middle phalanx III:

!$

........-----------------------------

m

------------------------------------.

m

-------------------------------------

Midd?fephalanx IV:

P75 -------------------- --------- . . . . . . . . . .

P50 ---------------------- ---------------

P ------------------ --------------------

Mid$fe phalanxV:

P7E---------------------------- ---------

--------------------------- ------------

;; -.--------., --------- -----------------

Distal phalanx I:

.-----..-----..--”-------------------

$: -.---”-----------------------.-..---.-

Di~t%l phalanx II

-------------..--.--.---.---..--”----

:

$“--------------------------- ----------

---------------------- -------------

Dtst2~lphalanx IZI:

-,--------------------------------------

& ------------------------------..-.----

D~t%l phalanx IV:

$_ 75-------------------------------------

Di ~;l phalanxV:

) ---------------------.................

Pg --------------------------- ----------

P~-------------------------------------

54

Boys -chronological age in years

6 7 8 9 10 11

Bone-specific skeletal age in months-male

standard

84.9

76.8

68.9

86.6

78.6

72.6

84.6

78.3

72.2

84.7

77.0

69.7

86.3

78.2

70.2

88.8

“80.6

74.3

;:.;

71:5

87.4

79*1

72.2

88.3

;;.:

●

82.8

74.4

64.5

85.8

76.4

69.0

84.7

76.2

68,3

84.5

75.8

66.8

84.7

76.4

67.6

94.3

87.3

80.2

99.0

89.3

81.3

96.9

88.6

80.7

96.8

88.5

80.7

97.7

89,2

80,9

1;;.;

83:6

99.5

::.;

●

100.5

91.6

81.8

102.2

91.0

81.3

96.3

87.3

78.9

99.9

f33.:

.

lCIO.0

88.8

80.5

100.2

89.0

80.3

100.3

89.0

80.2

.

106.5

96.6

88.7

110.1

100.6

90.6

110.1

m:. :

,

U&. :

90:0

110.6

101*o

90.4

109.4

105● o

92.3

108.7

102.5

91..3

109● 2

103.5

92,7

109.5

104.5

92.6

110.8

102.8

90.3

110,9

104.5

92.2

110.9

104.3

92.1

111.0

104.3

92.1

110.8

1;$ ;

.

154.8

154.1

152.5

155.4

153.7

153.4

114.2

1;:.;

.

115.2

109.9

98.6

115.1

109.3

97.0

115.6

m:. :

.

115.4

110.2

97.0

116,1

108.9

100.4

116,2

108,3

99.2

115.9

108.5

100.0

116.0

108.5

100.6

116.0

110.6

100,6

115.3

110.9

104*2

115.4

110.9

103.5

115.3

111.2

103.0

u?;

103:4

161.6

157.0

151.2

150.8

150.5

150.2

122.1

113.0

105.7

119.8

114.8

109● o

120.4

114.5

108.9

122.2

115*3

110.0

L21.2

115.1

110.2

123.2

115.5

108.5

L23.1

115.5

108.1

121.0

115,0

108.3

121.8

114.8

107.8

120.9

115.1

3.10.3

120.0

114.6

110.8

120.1

114.5

110.9

u:.:

110:7

120.0

114.8

110.7

160.4

157.1

152.6

164.2

160.2

156.3

132.7

123.3

114.7

132.7

;;$.:

.

132.9

122.3

115*3

134.1

123,7

116.2

135.0

123.9

115,8

g.:

116:7

135.3

125.3

116.8

133.0

123.7

116.2

136.6

124.3

116,2

134*1

123.4

116.1

132.9

L22.o

115.7

132.9

122.3

115.7

134.1

122.5

115.6

u;.;

115:7
Table 8. Selectedpercentilesin the distributio~of bone-specificskeletalages for each of the

31..hand-wristbone’sof boys and girls, by chronolo~icalage in years at last birthday:United

States, 1963-65-Con.

Girls—chronologicalage in years

6 7 8 9 10 11

Bone-specificskeletalage in months—male

standard

152.8

152.5

152.2

99.8

88.9

80,8

106.0

92.1

81.5

105● 7

:3.:

.

104.6

!?;.;

.

105.3

91.5

81.3

105.6

92.6

84.3

1;;.;

82:5

105.2

92.7

82.5

105.9

92.9

82.3

104.3

90.6

80.5

1;:.:

84:1

l;tl.;

82:9

104.4

93.0

82.8

1:;.;

82:6

154.6

150.9

150.5

160.8

160.5

160.2

112.1

102.8

90.5

114.1

107.3

92.7

114.0

107.6

92.3

114.2

106.4

92.4

114.1

106.7

92.7

;;$.:

93:9

113.6

105.2

92.3

113.1

106.0

94,0

113.6

106.0

92.8

113.5

1;;.;

.

113.9

108.1

95,5

114.1

107.8

94.5

114.0

108.0

94.4

113.8

107.2

94.6

160.2

153.4

150.6

171.5

152.8

150.7

120.9

112.9

104.7

119.9

114.3

108.8

120.2

114.2

108.5

120.7

114.7

108.1

122.1

114.5

198.9

122.7

114.9

107,3

122.3

114.5

106.0

120.6

114.3

106.3

12007

114.2

106.5

119.0

113.8

107.0

118.4

114*1

108.9

118.5

114.2

108.7

118.5

114.2

108.6

118.3

114.1

108.2

162.3

156.9

152.5

165.0

158.1

152.1

137.0

124.5

114.8

136.3

121.9

115.3

136.1

122.1

115.4

136.5

123.6

116.0

137.8

124.4

115.6

136.5

124.5

115.8

135.5

124.4

115.9

134.6

123.0

115.3

136.8

122.8

114.8

134.9

120.8

114.1

132.3

118.8

114.4

132.5

118.9

114.6

132.4

119.0

114.4

132.8

118.9

114.2

162.7

159.4

154.0

164.8

160.7

153.6

158.4

142.2

127.6

156.9

141.4

128.1

158.1

142.7

127.1

156.5

141.0

128.4

156.4

141.3

129.0

156.5

142.1

128.4

156.9

140.8

128.2

156.1

140.2

126.7

156.3

140,7

128.2

157.2

138.9

125.3

154.4

136.5

122.9

154.9

137.4

123.4

156.1

137.6

123.5

156.4

137.8

123.2

166.9

163.0

159.1

171.3

164.5

160.3

172.3

164.2

153.0

171.3

164.1

152.8

172.2

164.1

152.9

172.9

164.4

152.4

172.7

164.3

152.4

170.9

163.1

151.2

171.0

163.4

151.5

170.9

163.3

150.5

172.2

163.3

150.8

170.9

;;;.;

.

170.5

161.9

148.1

170.6

162.3

148.,6

170,9

162.6

148.8

171.0

162.4

150.7

Girls—chronological age in years

6 7 8 9 10 11

Bo~e-specificskeletalage in months—female

equivalent

125.8

125.5

125.2

84.8

74.8

65.9

91.0

77.1

66.5

90.7

76.0

65.8

89.6

76.6

65.9

;3.;

66:3

91.3

77.8

71.6

89.0

77.2

70.2

91.1

77.8

70.2

;$~

63:3

;3.;

66:5

90.3

78.6

69.1

91.6

78.8

67.9

91.1

79.0

67.8

89.8

77.9

67.6

127.2

124.9

124.5

131.4

131.2

131.1

98.1

87.8

75.5

99.1

92.4

77.7

99.0

92.9

77.3

99.2

91.4

77.4

100.1

91.7

77.7

99.6

91.8

78.9

98.9

;;.;

.

98.2

91.5

79.0

98.6

91.5

74.7

98.5

;:.g

.

98.9

93.6

80.5

100.1

93.8

80.5

100.0

’34.0

80.4

98.8

92.3

79.6

131.2

126.4

124.6

139.2

125.9

124.7

105.9

98.9

89.7

104.9

99.3

94.7

105.2

99.2

94.2

105.7

99.7

93.6

107.0

100.5

94.8

107.4

100.8

92,3

107.2

100.2

91.5

105.6

100.0

91.6

105.7

99.2

91.8

104.0

98.8

92.0

103.4

99.1

94.8

103.8

100.2

94.7

103.8

100.2

94.6

103.3

99.1

93.8

132.3

128.9

125.8

134.0

130.0

125.6

116.0

108.5

100.4

115.6

105.9

100.3

115.6

106.6

100.4

115.8

107.6

101.0

116.9

108.4

101.6

116.2

108.5

101.4

115.8

108.4

101.4

115.3

107.5

101.2

115.9

106.8

99.8

115.4

105.8

99.1

113.3

103.8

99.4

113.8

103.9

100.6

113.7

104.0

100.4

113.9

103.9

99.2

132.7

130.7

127.0

133.9

131.4

126.6

129.7

119.6

110.6

128.9

119.4

110.6

131.0

119.8

110.0

128.8

119.0

110.7

128.7

119.4

112.0

128.8

119.6

111.4

128.9

118.9

111.2

128.1

118.6

109.8

128.3

118.7

110.6

129.2

117.4

108 3

127.7

116.2

107.4

127.9

116.7

107.7

128.6

116.8

107.8

128.8

116.9

107.6

134.9

::;.:

.

M;.:

131:2

139.3

133.6

127.0

138.3

133.1

126.4

141.2

134.4

126.9

141.9

134.5

126.4

140.7

133.6

126.4

137.9

132.1

125.1

138.0

132.4

125.2

137.9

132.3

124.8

140.2

133.2

124.9

138.9

133.0

125.8

138.2

131.9

123.1

138.6

132.3

123.6

138.9

132.6

123.8

138.0

133.2

124.8

55
Table 9. Selected percentiles in the distribution of the individual child’s range in

bone-specific skeletal ages for the radio-opaque (not adult) bones in the hand-wrist

for boys and girls, by chronological age in years at last birthday: United States,

1963-65

Sex and chronological age in years

Boys

6 years ---------------------------------

7 years ---------------------------------

8 years ---------------------------------

9 years ---------------------------------

10 years --------------------------------

11 years --------------------------------

Girls

6 years ---------------------------------

7 years ---------------------------------

8 years ---------------------------------

9 years ---------------------------------

10 years --------------------------------

11 years --------------------------------

Percentile points

P,, P75 I

Pm I

P,, I

P,

Bone-specific skeletal .-age in months—

male standard

50.6

50.1

46.6

43.4

38.5

38.8

46.7

44.5

41.9

40.9

44.2

43.3

37.3

36.1

34.3

29.9

26.6

26.4

34.5

31.9

29.2

30.4

32.1

32.8

29.4

28.3

26.4

22.2

20.1

19.2

27.3

23.9

21.5

22.1

24.6

24.5

22.5

20.6

19.1

14.8

13.9

13.9

20.6

15.5

14.5

15.4

17.6

17.3

12.0

12.1

10.3

8.1

801

7.6

11.5

8.2

7.0

7.4

7.5

7.4

56
APPENDIX I

STATISTICAL NOTES

The Survey Design

The sample design for the second cycle of the Health

Examination Survey, similar to the one used for the

first cycle, was that of a multi-stage, stratified probability sample of loose clusters of persons inland-based

segments. Successive elements dealt with in the process of sampling are primary sampling unit (PSU),

census enumeration district (ED), segment, household,

eligible child (EC), and finally, the sample child (SC).

At the first stage, the nearly 2,000 PSU’s into which

the United States (including Hawaii and Alaska) has been

divided and then grouped into 357 strata for use in the

Current Population Survey and the Health Interview

Survey were further grouped into 40 superstrata for

use in Cycle H of the Health Examination Survey. The

average size of each Cycle II stratum was 4.5 million

persons, and all fell between the limits of 3.5 and 5.S

million. Grouping into 40 strata was done in a way that

maximized homogeneity of the PSU’S included in each

stratum, particularly with regard to degree of urbanization, geographic proximity, and degree of industrialization. The 40 strata were classified into four broad

geographic regions (each with 10 strata) of approximately equal population and cross-classified into four

broad population density groups (each having 10 strata).

Each of the 16 cells contained either two or three

strata. A single stratum might include only one PSU

( or only part of a PSU, as for example New York City,

which represented two strata) or several score PSU’S.

To take account of the possible effect that the rate

of population change between the 1950 and 1960 censuses

might have had on health, the 10 strata wi’dtin each region were further classified into four classes ranging

from those with no increase to those with the greatest

relative increase. Each such class contained either two

or three strata.

One PSU was then selected from each of the 40

strata. A controlled selection technique was used in

which the probability of selection of a particular PSU

was proportional to its 1960 population. In the controlled

selection an attempt was also made to maximize the

spread of the PSU’S among the States. While not every

one of the 64 cells in the 4x4x4 grid contributes a PSU

to the sample of 40 PSU’S, the controlled seIection

technique ensured the sample’s matching the marginal

distributions in all three dimensions and being closely

representative of all cross-classifications.

Generally 20 ED’s were selected within a particular

PSU. The probability of selection of a particular ED

was proportional to its population in the age group 5-9

years in the 1960 census, which by 1963 roughly approximated the population in the target age group for

Cycle II. A similar method was used for selecting one

segment (cluster of households) in each ED. Each of

the resultant 20 segments was either a bounded area or

a cluster of households (or addresses). All the children

in the age range 6-11 years normally resident at each

household or address were considered EC’S. Operational considerations made it necessary to reduce the

number of prospective examinees at any one location

to a maximum of 200. The EC’s to be excluded for this

reason from the SC group were determined by system.

atic subsampling.

The total sample thus selected for the examination

included 7,417 children from 25 different States in the

age group 6-11 years with approximately 1,000 in each

of the single years of age.

Reliability

Measurement and assessment processes employed

in the survey were highly standardized and closely controlled. Of course this does not mean that the correspondence between the real world and the survey results is exact. Data from the survey are imperfect for

three major reasons: (1) results are subject to sampling error, (2) the actuaI conduct of a survey never

agrees perfectly with the design, and (3) the measurement or assessment processes themselves are inexact

even though standardized and controlled.

The first report on Cycle II 4 describes in detail

the faithfulness with which the sampling design was

carried out. It notes that 7,119 out of the 7,417 sample

children were examined. This is a response rate of 96

percent. The examined children were a highly representative sample of this age in the noninstitutional population of the United States. The response levels for

57
the various demographic subgroups, including those

for age, sex, race, geographic region, population density, parent’s educational level, and family income

show no marked differentials. Hence it appears unlikely that nonresponse could have biased the findings

markedly in these respects. Further description of the

sample design and estimation procedures are contained

in a subsequent report. 93

The general measures used to control the quality

of data from this survey have been cited previously; 4’94

those relating specifically to the assessment of skeletal age are outlined in this report.

Data recorded for each sample child are inflated

in the estimation process to characterize the larger

universe of which the sample child is representative.

The weights used in this inflation process are a product of the reciprocal of the probabili~ of selecting

the child, an adjustment for nonresponse cases, and a

poststratified ratio adjustment which increases precision by bringing survey results into closer alignment

with known United States population figures by color

and sex within single years of age 6-11.

In the second cycle of the Health Examination Survey the sample was the result of three stages of selection-the single PSU from each stratum, the 20 segments from each sampIe PSU, and the sample children

from the eligible children. The probability of selecting

an individual child is the product of the probability of

selection at each stage.

Since the sixata are roughly equal in population

size and a nearly equal number of sample children was

examined in each sample PSU, the sample design is

essentially self-weighting with respect to the target

population, that is, each child 6-11 years old had about

the same probability of being drawn into the sample.

The adjustment upward for nonresponse is intended to minimize the impact of nonresponse on final

estimates by imputing to nonrespondents the characteristics of “similar” respondents. Here “similar”

respondents were judged to be examined children in a

sample PSU having the same age in years and sex as

children not examined in that sample PSU.

The poststratified ratio adjustment used in the

second cycle achieved most of the gains in precision

that would have been attained if the sample had been

drawn from a population stratified by age, color, and

sex and made the final sample estimates of population

agree exactly with independent controls prepared by

the Bureau of the Census for the noninstitutionalized

population of the United States as of August 1, 1964

(approximately midsurvey point), by color and sex for

each single year of age 6-11. The weights of every responding sample child in each of the 24 age, color, and

sex classes is adjusted upward or downward so that

the weighted total within the class equals the independent population control.

In addition to children not examined at all, there

were 157 for whom the radiograph could not be asTable 1. Number of examined children whose handwrist radiographs were assessed and those that

were not assessed for skeletal age by chronological age in years and sex: Health Examination Survey, 1963-65

Chronological

age at last

birthday

6

7

8

9

Total -------

years -----------

years -----------

years -----------

vears -----------

10” years ----------

11 years ----------

m

Number of children

3,545

554

615

602

582

570

622

3,417

521

602

600

562

576

556

21 15

17

16 1;

21 19

6 8

6 8

sessed. The age and sex distribution for these 157

children aa well as for the 6,962 for whom assessments

were made is shown in table I. No attempt was-made

to estimate the skeletal age for the group of children

without usable radiographs. Hence it is assumed that

the distribution of their skeletal ages is similar to that

for the remaining 6,962. In other words they were treated

as if they were nonrespondents.

Among the 6,962 children with usable radiographs,

there were a few for which the film quality was not

goad enough to permit assessment of all ossifying or

ossified bones. In general these would have been bones

that had become radio-opaque recently. The numbers

of children for whom bone-specific skeletal ages were

assessed and in which the bone was considered as ossifying or completely ossified (adult) are shown in table

..

11.

Sampling and

Measurement Error

In the present report, reference has been made to

efforts to minimize bias and variability of measurement techniques.

The probability design of the survey makes possible the calculation of sampling errors. The sampling

error is used here to determine how imprecise the survey test results may be because they come from a sample rather than from the measurements of all elements

in the universe.

The estimation of sampling errors for a study of

the type of the Health Examination Survey is difficult

for at least three reasons: (1) measurement error and

“pure” sampling error are confounded in the data—it is

not easy to find a procedure which will either com58
Table II. Number of boys and girls for whom

skeletal age assessments were made on each of

the 31 hand-wrist bones: Health Examination

Survey, 1963-65

Bone

Raclius-------------

Ulna---------------

Cavitate-----------

Hamate-------------

Triquetral---------

Lunate-------------

Scaphoid-----------

Trapezium----------

Trapezoid----------

Metacarpal I-------

lfetacarpalII------

Metacarpal III-----

Metacarpal IV------

Metacarpal V-------

Proximal phalanx IProximal

phalanx II--------

Proximal

phalanx III-------

Proximal

phalanx W--------

Proximal phalanx VMiddle phalanx II--

Middle phalanx IIIMiddle phalanx IV--

Middle phalams V---

Distal phalanx I---

Distal phalanx II--

Distal phalanx IIIDistal phalanx IV--

Distal phalanx V---

Pisiform-----------

Adductor sesamoid--

??lexorsesamoid----

Radio-opaque, I

Adult not adulta

Boys I

Girls Boys Girls

Number of children

3,540

2,806

3,540

3,540

3,518

3,448

3,151

3,046

3,180

3,538

3,541

3,542

3,542

3,542

3,539

3,5&2

3,543

3,543

3,543

3,538

3,536

3,538

3,526

3,533

3,532

3,531

3,532

3,532

746

88

21

3,417

3,201

3,375

3,387

3,322

3,363

3,352

3,311

3,338

3,409

3,411

3,411

3,411

3,410

3,407

3,410

3,410

3,406

3,406

3,405

3,411

3,410

3,388

3>371

3,380

3,383

3,387

3,382

1,789

837

321

.

.

-

.

-

.

-

-

.

.

.

-

.

.

.

.

.

.

.

aIn long and short bones, radio-opaque

refers to the epiphyses.

pletelyinclude both or treatone or the otherseparately,(2)thesurveydesignand estimationprocedure

are complex and accordinglyrequire computationally

involvedtechniquesfor the calculationof variances,

and (3)thousandsof statisticscome from thesurvey,

many for subclassesof thepopulationforwhich there

are few cases. Estimates of sampling error are obtainedfrom the sample data and are themselvessubject to sampling error which may be large whenthe

number ofcases ina cellissmaller occasionallyeven

when the number of cases is substantial.

Estimates of approximate sampling variability for

selected statistics used in this report are presented

in the detailed tables. These estimates have been prepared by a replication techniq~e that yields overall

variability through observation of variability among

random subsamples of the total sample. The method

reflects both “pure” sampling variance and a partof

the measurement variance.

In accordance with usual practice, the interval

estimate for any statistic may be considered the range

within one standard error of the tabulated statistic

with 68-percent com%lence or the range within two

standard errors of the tabulated statistic with 95-percent confidence. The latter is used as the level of significance in this report.

An approximation of the standard error of a difference d= x -y of two statistics x and y is given by

the formula s~= (St+ S; )”2 where SX andSY are the

sampling errors, respectively ofxand y.

Small Categories

In some tables magnitudes are shown for cells for

which the sample size is so small that the sampling

error may be several times as great as the statistic

itself. Obviously in such instances the statistic has no

meaning in itself except to indicate that the true quantity is small. Such numbers, if shown, have been included in the belief that they may help to convey an impression of the overall story of the table.

000

59
APPENDIX II

RELIABILITY OF ASSESSMENT

To provide the basis for determining the level of

reliability of the bone-specific skeletal age assessments made by the six medical students at Case Western Reserve University from hand-wrist radiographs

of the children 6-11 years old who were examined in

the Health Examination Survey of 1963-1965, a randomly

selected sample of one in 24 films was reassessed by

the same reader and approximately one in 24 independently randomly selected films was reassessed by another. Before starting these final assessments, all six

readers were trained by Dr. Pyle in the Greulich-Pyle

method using the HES Standard to the point that their

ratings were in close agreement with hers. In all, 297

self-replicate assessments and 288 cross-replicate

assessments were obtained. Thus each reader made

approximately the same number of self-replicate and

cross-replicate assessments.

All six readers maintained a Klgh level of consistency in their own assessments throughout all 40

stands of examinations in the survey. The mean difference in self-replicate assessments for all six readers

combined was 0.8 month for all 31 bones and just

slightly less—O.7 month—if the bones that are late to

ossify (the pisiform, adductor sesamoid, and flexor

sesamoid) are excluded. Considering data from all 31

Imnes the mean difference per reader between his original and self-replicate assessments ranged from 0.0 to

1.4 months (combining data for the two sexes). For the

28 bones that ossify relatively early, the mean differences ranged from 0.0 to 1.5 months among the six

readers (table III).

A consistently high level of agreement in bonespecific skeletal age assessments was also maintained

among the six readers, but as expected, the level was

Table III. Mean difference in cross- and self-replicate assessments of bone-specific skeletal ages from hand-wrist

radiographs of examinees 6-11 years old at laat birthday, by reader: Health Examination Survey, 1963-65

Assessor

Both sexes

Assessor 1---

Assessor 2---

Assessor 3---

Assessor 4---

Assessor 5-..

Assessor 6---

Boys

Assessor 1---

Assessor 2---

Assessor 3---

P.ssessor 4---

Assessor 5---

Assessor 6---

g

Assessor 1---

Assessor 2---

Assessor 3---

Assessor 4---

Assessor 5---

Assessor 6..-

Self-replicates Cross-replicates

T;?

Hsnge in mean Average mean Hsnge in mean

differences

Average mean

difference

replication

differences difference

1 1

31 bones 28 bonesa 31 bones 28 bonesa 31 bones 28 bOnesa 31 bones 28 boneS= Cross Self

0.0-1.8

0.0-7.0

0.1-3.0

0.1-2.4

0.1-4$7

0.6-3.6

0.1-1.8

0.0-7.0

0.1-3.0

0.0-2.1

0.1-4.7

0.1-3.5

0.0-1.0

060:-+.:

0:1:2:4

0.1-2.7

0.6-3.6

0.0-1.8

0.0-2.5

0.1-2.1

0.1-2.4

0.1-4.7

0.6-3.6

0.1-1.8

0.0-2.5

0.1-2.1

0.0-2.1

0.1-4.7

0.1-3.5

0.0-0.9

0.03-1.7

0.1-1.6

0.1-2.4

0.1-2.7

0.6-3.6

0.0

:::

0:7

1.4

:::

0.3

0.4

1.0

1.6

0.0

0.3

lk:

0.5

0.8

Months of skeletal age

::$

:::

0.9

1.2

0.0

0.4

:::

0.6

1.7

0.7-10.7 0.7-10.7 3.6

0.04 -10.5 0.04-7.5

0.03-5.6 0.03-5.6 -::;

0.1-13.1 :.:-:.; -1.2

0.1-7.0 -3.3

0.2-5.1 0:2=5:1 1.4

0.6-10.7 0.6-10.7 3.8

0.03-7.5 0.03-7.5

0.3-5.5 0.3-5.5 -i::

0.1-6.7 0.1-6.7 -1.0

0.1-6.5 0.1-6.3 -;.;

0.7-5.1 0.7-5.1

aExcluding the pisiform, adductor sesamoid, and flexor sesamoid.

Number of

bones assessed

3.7 724

1,771

-$:: 2,130

-1.3 970

-3.2 1,395

1.5 1,415

1

3.9 360

932

-::; 1,063

-1.4 461

-3.0 50?.

2.0 863

3.5 364

839

-i:; 1,067

-1.2 509

-3.9 893

1.1 552

758

1,694

1,869

936

1,293

1,597

384

869

889

477

710

612

374

825

980

459

583

985

60
somewhat lower than that for the individual readers

with themselves. On all 31 hand-wrist bones, the mean

cross-replicate differences between the original and

the replicate assessment by another reader was 0.0

months. It ranged between +1.4 and +3.6 months for

three of the readers and -1.2 to -3.3 for the other three

readers. When only the 28 centers that ossify relatively early are considered, the overall mean difference

was nearly identical to that for all 31 bones (table IV).

A further independent test of the validity and reliability of the skeletal age assessments in this study

was made on a randomly selected group of 50 handwrist radiographs among the 1l-year-old Imys in the

national study. These 50 films were reassessed independently by an assessor at Fels Research Institute

who was proficient in the use of the Greulich-Pyle

method but had not been trained by Dr. Pyle. The assessor at Fels Institute was not told the age or sex of

the children nor did she have access to the previous

skeletal age assessments. Her mean skeletal age (handwrist) for the 50 radiographs was O.7 month lower than

the original assessment for them in the national study.

Her mean bone-specific skeletal ages ranged from 3.6

months greater on the scaphoid to 2.9 months less on

the ulna than the original assessments (table V).

The aspects considered include consistency within

observers (intraobserver differences), comparability

between observers (interobserver differences), and

differences resulting from variations in the way the

GreuJ.ich-Pyle Atlas was used. This review is restricted to reports based on samples of at least 10 radiographs and in the chronological age range 6-11

years.

While it is impossible to determine the true ma.

turity level of the bones visualized in a radiograph,

the reliability of assessments should be defined both

within and between observers. Greulich and Pyle 5 contend that though the ability to duplicate assessments

Table IV. Mean differences among six assessors in cross - and self -replicate assess -

ments of bone-specific skeletal ages from hand -wrist radiographs of examinees 6-11

years old at last birthday, by bone: Health Examination Survey, 1963-65

Hand-wrist bone

~:p -------------------------------------

-------- ----------------------------- --

-Cavitate -----------------------------------

Hamate -------------------------------------

Triquetral ---------------------------------

Lunate -------------------------------------

Scaphoid -----------------------------------

Trapezium ----------------------------------

Trapezoi,d ----------------------------------

MetacarpalI --------------------------------

Metacarpal 11------------------------------

Metacarpal III-----------------------------

Metacarpal IV------------------------------

Metacarpal V-------------------------------

Proximal phalanx I-------------------------

Proximal phalanx II------------------------

Proximal phalanx III-----------------------

Proximal phalanx IV------------------------

Proximal phalanx V-------------------------

Middle phalanx

Middle phalanx

Middle phalanx

Mf.ddle phalanx

Distal phalanx

Distal phalanx

Distal phalanx

Distal phalanx

Distal phalanx

II--------------------------

111-------------------------

IV--------------------------

v ---------------------------

I---------------------------

11--------------------------

111-------------------------

Iv--------------------------

v ---------------------------

Pisiform -----------------------------------

Adductor sesamoid --------------------------

Flexor sesamoid ----------------------------

Months of skeletal age

0.8

0.3

0.2

0.4

1.2

0.1

0.2

0.3

0.4

0.9

:::

0.7

0.7

0.8

:::

0.8

0.4

%2

0.5

0.9

0.2

::;

%;

0.3

0.5

0.4

0.4

0.2

0.5

0.3

1.6

0.0

0.2

%;

1.0

1.1

0.7

:::

0.5

0.2

;:;

0.5

::;

0.7

1.0

::2

0.5

0.9

0.7

0.4

::;

H

0.2

0.5

0.6

0.2

U

0.4

0.9

1.1

0.7

N

1.2

0.4

%;

0.4

0.5

0.3

0.3

0.8

0.2

0.3

0.6

0.6

0.4

0.2

0.4

0.6

0.0

0.0

:::

u

0.1

0.3

0.0

0.0

0.6

0.0

0.0

0.0

::8

0.0

0.0

0.0

0.0

0.0

%:

0.0

0.0

0.0

:::

::;

3.6

‘0.1

0.0

0.0

0.0

0.0

0.6

0.0

%;

0.0

0.7

:::

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

:::

0.0

0.1

%;

0.0

0.1

0.0

0.0

0.1

0.1

0.2

0.1

0.4

0.2

0.2

0.0

:::

0.1

0.1

0.1

0.1

0.1

0.1

0.1

0.1

0.1

%:

0.0

0.1

0.0

0.0

0.0

0.1

61
Table V. Hean difference on 50 radiographs of

n-year-old boys between original a~sessment

at Western Reserve University and reassessment

at Fels Institute: Health Examination Survey,

1963-65

Hand-wrist bone

Total -----------------------

Radius ----------------------------

Ulna ------------------------------

Capitate --------- ..”----- ..-”..-. . .

Harnate ----------------------------

‘Jkiquetral ------------------------

Lunate ----------------------------

Scaphoid --------------------------

Trapezium -------------------------

~rapezoid -------------------------

Metacarpal I----------------------

Metacarpal II---------------------

Metacarpal III--------------------

Metacarpal IV---------------------

Metacarpal V----------------------

Proximal phalanx I----------------

Proximal phalanx II---------------

Proximal phalanx III--------------

Proximal phalanx IV---------------

proximal phalanx V----------------

Middle phalanx II-----------------

Middle phalanx III----------------

Middle phalanx IV-----------------

Middle phalanx V------------------

Distal phalanx I------------------

Distal phalanx II-----------------

Distal phalanx III----------------

Distal phalanx IV-----------------

Distal phalanx V------------------

Pisiform --------------------------

Adductor sesamoid -----------------

Flexor sesamoid -------------------

Mean

difference

In months

-0.7

-0.1

-2.9

-2.8

-1.6

+0.9

+1.0

+3.6

+1.7

+0.9

+1.4

+0.3

+0.5

0.0

-0.3

-1.3

-2.6

-1.2

-1.5

-1.5

+0.9

-0.3

-1.7

-0.7

+1.2

-1.6

-1.9

-1.6

-2.0

-2.6

-0.5

with a good degree of consistency must repossessed

by a competent assessor, it alone isnotenough. It is

even more important that the assessments be made

correctly, that is, that they be made accordingto the

method recommended by the particular radiographic

atlas onwhich they purport to be based. Unfortunately,

the suggestion by Moore95that sets of duplicate radiographs which have been assessed by recognized

experts be available to those who wishtomeasure their

level of comparability has not been implemented.

Area Skeletal Ages

It is not easy to compare reported findings because workers have analysed their data in different

ways. For intraobserver differences, 95-percent confidence limits of 7.2 monthsgs and mean differences

ranging fronf 1.2 to 6.6 months have been reported, 53’97-100 in addition to variable errors of 1.4

to 4.2 months. 101J02 The medim intraobserver differences range from zero to 4 months,1°3-105 A report of zero median differences seems surprising at

first, butitis~ssible becauseMoedandhis coworkers

made overall assessment tothenearest atlas standard.

The reliabilityof the HESdata compares favorably with

the preceding studies. Todd’s claim45 that interobserver difference of less than 6 months could be

achieved readily appears justified. Reported mean

interobserver differences range from 1.3 to 4.2

months?3,’06’107 in addition, a root mean square of 6.2

months and confidence limits of 7.4 months have been

reported. gs’loo Reported incidence of particular interobserver differences indicate that the medians were

less than 3 months for the study by Hansman and

Maresh’08 and less than 6 months for the study by

Moed et al 1°3 The mean interobserver differences

.

among readers in the Health Examination Survey are

toward the lower end of the sample values reported

by others.

Bone-Specific

Skeletal Ages

Few have reported relevantdata.The intraobserver

differences were slmost all less than 3months in the

105 Mooren reported in- study of Sproul and Peritz.

terobserver differences that were less than 12 months

in 94 percent of bones.

Factors Influencing

Replica bility

There is no indication that the levelof replicability

is related to the difference between chronological and

skeletal age. 98’101 However, the range of maturity

between the bones of ahand-wrist influences the repliability of overall but not bone-specific assessments.53,98 The quality of the radiographs (exposure,

positioning) has no effect on replicability within the

range usual in research studies,53 but unusually poor

radiographic quality does reduce replicability.l”l The

method by which theGreulich-Pyle Atlas5 is used has

an effect. Maresh60 reported a technical error of3.Cl

months between overall assessments and those obtainedas the means of bone-specific skeletal ages.The

direction of these differences wasnotreported. Sproul

and Peritz78 considered assessment more difficultin

short or tall children and in the hamate and seccmd

metacarpal than in other hand-wrist bones. The latter

statement has not been confirmed in the Health Examination Survey on either self- or cross-replication

data.

62
VITAL AND HEALTH STATISTICS PUBLICATION SERIES

Originally Public Health Service Publication No. 1000

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Center for Health Statistics and its offices and divisions, data collection methods used, definitions,

and other material necessary for understanding the data.

Series 2. l%ta evaluation and methods research. — Stuclies of new statistical methodology including: experimental tests of new survey methods, studies of vital statistics collection methods, new analytical

techniques, objective evaluations of reliability of collected data, contributions to statistical theory.

Series 3. Analytical studies -—Reports presenting analytical or interpretive studies based on vital and health

Series 4.

Series 10.

Series 11.

Sw”es 12.

Series 13.

Se7ies 14.

Series 20.

Sm”es 21.

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