bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the entoconulid (sixth cusp) on mandibular molar teeth of an Australian aboriginal population
Authors: Townsend Grant , Yamada Hiroyuki , Smith Patricia 
Published: February 2006

AbstractThe expression and genetic basis of the entoconulid (sixth cusp) on mandibular molars were examined in a geographically isolated group of aboriginals from Yuendumu in the Northern Territory of Australia. Four grades of trait expression, ranging from trace to small, medium, and large cusps, were defined on dental casts of 399 subjects. Frequencies of occurrence were among the highest reported in human populations. Approximately 80% of dm2s showed the trait, whereas frequencies in the permanent dentition ranged from around 50% on M2 to 70% on M1 and 80% on M3. The degree of expression increased distally along the molar series, with only 3% of dm2s showing large cusps compared with 25% of M3s. Fluctuating asymmetry was highest for M2 and lowest for dm2. No strong evidence for sexual dimorphism in occurrence or degree of expression was found.Based on a quasi‐continuous threshold model, a genetic contribution to entoconulid variability was observed that was strongest for M1. Significant associations were noted between entoconulid expression on mandibular molars and metaconule expression on maxillary molars, indicating that similar developmental mechanisms may influence these traits. The entoconulid and the metaconule both provide additional bulk on the distal occlusal surface of molar teeth, an area subjected to early wear during mastication in aboriginals.
Polynesian face and dentition: Functional perspective
Authors: Kean M. R. , Houghton P. 
Published: February 2006

AbstractWidely dispersed throughout the Pacific, Polynesians are a biologically distinctive people in form and size of both body and head. Largebodied and well‐muscled, their body phenotype is suited to life in a thermolabile oceanic environment. Their craniofacial skeleton is large and robust, with mandibular size and from (the “rocker” mandible) being especially characteristic. In this paper the Polynesian variants of body form, and of facial size (including dentition) and form, are interpreted from a functional perspective.
Tooth wear and temporomandibular joint change in Australian Aboriginal populations
Authors: Richards L. C. 
Published: February 2006

AbstractThe masticatory system consists of teeth, temporomandibular joints, and the supporting craniofacial skeleton. The form and function of each of these components of the system can be understood only within the overall context of the system.In a series of studies, the complex relationships between tooth wear and temporomandibular joint morphology and pathology were considered in samples consisting of a total of 58 male and 54 female crania from two Australian Aboriginal populations. The extent and buccolingual direction of tooth wear were assessed using established techniques. Both metric and nonmetric description of temporomandibular joint morphology and pathology were developed.Significant differences in patterns of tooth wear and in the frequencies of various temporomandibular joint changes were evident between sexes and between populations. Furthermore, significant correlations between a number of tooth and joint variables were also evident. In addition, there was clear evidence of relationships between both tooth wear and temporomandibular joint changes and craniofacial morphology.The results of this study provide additional evidence of the complex relationships between the form and function of the masticatory system.
Patterns of enamel hypoplasia in two medieval populations from Nubia's Batn el Hajar
Authors: van Gerven Dennis P. , Beck Rosemary , Hummert James R. 
Published: February 2006

AbstractAnalysis of enamel hypoplasia frequencies for two medieval populations representing the earliest and latest Christian periods of ancient Nubia reveals important diachronic shifts in childhood stress. The mean frequency for hypoplastic bands among the early Christians is 4.2, while the late Christian sample has a mean frequency of 3.7. In addition, the earlier Christians show a prolongation of hypoplastic occurrences through childhood corresponding to a prolonged period of intensified childhood mortality. The modal time interval between hypoplastic occurrences is also shorter for the early Christian children.A comparison of hypoplasia frequencies by sex also reveals a pattern of considerable interest. Females show both lower frequencies of hypoplasias as well as a delay in onset.The diachronic differences are consistent with other indications from paleopathology and paleodemography that childhood stress decreased in later Christian times. The sex differences suggest that during the infancy and early childhood females were more resilient than their male counterparts.
The effects of population structure on the spread of the HIV infection
Authors: Sattenspiel Lisa , Koopman James , Simon Carl , Jacquez John A. 
Published: February 2006

AbstractA model for the spread of human immunodeficiency virus (HIV) in a population of male homosexuals is presented. The population is divided into five groups on the basis of degree of sexual activity. Within each group, the individuals are classified as (1) susceptible; (2) infective; or (3) removed because of a lack of sexual activity associated with advanced acquired immunodeficiency disease (AIDS). The infective individuals are further subdivided into four stages of infection. Analyses of the model address two questions with regard to the spread of HIV: (1) What is the effect of level of sexual activity on an individual's risk for infection, and (2) What is the effect that assumptions about mixing between groups have on both individual risk and transmission throughout a population? Results from analyses using a number of different parameter estimates show that increased levels of sexual activity increase the likelihood that an individual will become infected. In addition, the initial spread of the disease is markedly affected by variation in the amount of contact among individuals from different subpopulations. The steady‐state incidence of the disease is not markedly affected by variation in the contact patterns, but the size of the steady‐state population and therefore the proportion of infected individuals in the population does vary significantly with changes in the degree of mixing among subpopulations. These results show clearly the sensitivity of model outcomes to variation in the patterns of contact among individuals and the need for better data on such interactions to aid in understanding and predicting the spread of HIV.
Rheumatoid arthritis “in the buff”: Erosive arthritis in defleshed bones
Authors: Rothschild Bruce M. , Woods Robert J. , Ortel Wade 
Published: February 2006

AbstractExamination of isolated bones from patients with unequivocal rheumatoid arthritis provides only a glimpse of the disease but has been the only “gold standard” for recognition of osseous lesions as compatible with the diagnosis of rheumatoid arthritis. Documentation of skeletal pathologic changes in confidently diagnosed individuals has been a major missing link in the transition from clinical to skeletal analysis. Availability of appropriate skeletal material from two patients with long‐standing, well‐documented rheumatoid arthritis provided the opportunity for acquiring such information. The osseous appearance, skeletal distribution, and distinguishing features of rheumatoid arthritis “in the buff” were delineated in two contemporary patients and in a skeletal population of 2,906 individuals. The preconceived notion of anticipated severity of disease has hereby been tested and found wanting. Severe lesions are not recognizable or distinguishable from artifact in relatively fragile rheumatoid arthritis‐affected bones, whether freshly prepared or remotely sampled. Characterization of the nature and epidemiology of osseous alterations in two contemporary skeletal populations permitted the development of a standard for recognition of the disease in skeletal populations.
Continuing periosteal apposition I: Documentation, hypotheses, and interpretation
Authors: Lazenby Richard A. 
Published: February 2006

AbstractContinuing periosteal apposition (CPA) of small amounts of new lamellar bone, leading to absolutely larger size, has been identified in a number of adult cranial and postcranial bones. This paper reviews 42 studies published since 1964 that have found both significant and nonsignificant age‐related change in various skeletal size dimensions, e.g., length, diameter, width, and area. Also considered are four hypotheses that have, or may be, postulated for the occurrence of CPA. To date, however, these hypotheses (cohort effect, mechanical compensation, bone repair and/or mechanical response potential, and heterochrony) have not been rigorously tested, hence remain speculative. An important interpretive problem that befalls the investigation of CPA is its small effect size (i.e., the magnitude of change between observations), since most studies have restricted sample sizes. This problem is illustrated by power analysis of three reviewed studies that reported nonsignificant age‐related change. The analysis indicates that these studies had very little likelihood of finding a statistically significant result, i.e., a low probability of rejecting the null hypothesis stipulating no size change with age. This finding has implications for interpreting CPA and for distinguishing between the statistical and biological significance of this phenomenon.
Continuing periosteal apposition II: The significance of peak bone mass, strain equilibrium, and age‐related activity differentials for mechanical compensation in human tubular bones
Authors: Lazenby Richard A. 
Published: February 2006

AbstractIt is generally presumed that compensation for the reduction of bone strength by progressive endosteal bone loss in adults is provided by continuing periosteal apposition (CPA) of new lamellar bone. However, the appropriate magnitude of compensatory bone growth, and the parameters that operate to determine that magnitude, are unknown. This paper examines the mechanical compensation hypothesis in a series of right‐circular tubular bone analogues. Under this hypothesis, the stated objective of CPA is maintenance of the cross‐sectional geometric properties of the element. These include the second and polar moments of area, as well as the cortical area of the section (I, J, and CA, respectively). This study assumes that, as resorption and apposition proceed, geometric change is isometric (shape preserving).The analysis suggests that for a given rate of endosteal bone loss (the stimulus), the magnitude of periosteal growth (the response) required to maintain geometric strength is determined by the maximum ratio (CT0) of the radial distances from the section centroid to the endosteal and periosteal surfaces (i.e., cortical thickness prior to the onset of progressive endosteal bone loss, or peak bone mass). The analysis also indicates that, for any given individual, the amount of compensatory periosteal gain required may be very small. This is particularly true for individuals having a large CT0 and for whom the magnitude of dynamic loading imparted to the skeleton declines with advancing age. This finding is illustrated in a model that relates concepts of bone surface remodeling equilibria and age‐related activity differentials.
Comparison of muscle weight and force ratios in new and old world monkeys
Authors: Bouvier Marianne , Tsang Stephen M. 
Published: February 2006

AbstractThin mandibles and small incisors found in New World monkeys as compared with Old World monkeys suggest that there may be differences in craniofacial loading patterns between these two groups, particularly in levels of mandibular corpus twisting (Hylander, 1975, 1979a; Eaglen, 1984; Bouvier, 1986a,b). This study examined the hypothesis that changes in the relative force contributions of the masticatory muscles were responsible for lowering torsion on the mandibular corpus in New World monkeys. Muscle weight and physiological cross‐sections were compared using data from the literature (Schumacher, 1960; Turnbull, 1970; Cachel, 1979) as well as new data on adult male Cebus apella and Macaca mulatta. Both age and sex had an effect on muscle ratios. Mixed samples such as those used by Schumacher and Turnbull probably are not appropriate for drawing conclusions concerning species or group differences in muscle ratios. In addition, biomechanical conclusions based on muscle weight ratios alone to estimate muscle force may be misleading because fiber length inversely affects the amount of force a muscle can exert. A comparison of ratios based on physiological cross‐section as an estimator of muscle force in New and Old World monkeys does not support the hypothesis that alterations in force contribution by individual masticatory muscles are responsible for minimizing mandibular corpus twisting in New World monkeys. Therefore, if twisting has been minimized in New World monkeys as suggested by their thin corpora, other changes in the craniofacial musculoskeletal complex, such as different muscle recruitment or pinnation patterns, may be responsible.
Cladistics and the hominid fossil record
Authors: Trinkaus Erik 
Published: February 2006

AbstractCladistic methodology has become common in phylogenetic analyses of the hominid fossil record. Even though it has correctly placed emphasis on morphology for the primary determination of affinities between groups and on explicit statements regarding traits and methods employed in making phylogenetic assessments, cladistics nonetheless has limitations when applied to the hominid fossil record. These include (1) the uncritical assumption of parsimony, (2) uncertainties in the identification of homoplasies, (3) difficulties in the appropriate delimitation of samples for analysis, (4) failure to account for normal patterns of variation, (5) methodological problems with the appropriate identification of morphological traits involving issues of biological relevance, intercorrelation, primary versus secondary characters, and the use of continuous variables, (6) issues of polarity identification, and (7) problems in hypothesis testing. While cladistics has focused attention on alternative phylogenetic reconstructions in hominid paleontology and on explicit statements regarding their morphological and methodological underpinnings, its biological limitations are too abundant for it to be more than a heuristic device for the preliminary ordering of complex human paleontological and neontological data.
Metatarsophalangeal joints of Australopithecus afarensis
Authors: Latimer Bruce , Lovejoy C. Owen 
Published: February 2006

AbstractMetatarsophalangeal joints from African pongids, modern humans, and Australopithecus afarensis are compared to investigate the anatomical and mechanical changes that accompanied the transition to terrestrial bipedality. Features analyzed include the shape and orientation of the metatarsal heads, excursion of the metatarsophalangeal joints, and orientation of the basal articular surface of the proximal phalanges. These features unequivocally segregate quadrupedal pongids and bipedal hominids and demonstrate a clear adaptation to terrestrial bipedality in the Hadar pedal skeleton.
Three‐dimensional computed tomography of the mummy Wenuhotep
Authors: Pickering Robert B. , Conces Dewey J. , Braunstein Ethan M. , Yurco Frank 
Published: February 2006

AbstractComputed tomography allows cross‐sectional imaging of anthropological as well as clinical subjects. Recently, technical innovations have made three‐dimensional reconstruction of these images feasible. We performed two‐dimensional and three‐dimensional computed tomography of a Late Period Egyptian mummy to reexamine findings seen on previous radiographic studies and to evaluate the usefulness of these techniques in paleopathology.Two‐dimensional images provided excellent anatomic detail. There was graphic depiction of the mummification process that corroborated information previously obtained from Egyptological studies. Three‐dimensional reconstruction provided images of facial features as if the mummy had been unwrapped.Three‐dimensional computed tomography is a useful method of nondestructively evaluating paleopathological remains, and it may yield information not obtainable by any other means.
Caries experience in Mediaeval Scots
Authors: Kerr N. W. , Bruce M. F. , Cross J. F. 
Published: February 2006

AbstractDental caries prevalence, distribution, and site of attack was investigated in a Scottish Mediaeval population. The findings supported previous reports, which suggested that caries prevalence in Scotland was lower than in contemporaneous English populations. Attrition of the occlusal surface of the teeth with accompanying alteration of the anatomy of the interproximal space is suggested as the principal reason for the differences in the pattern of distribution of caries between this and modern populations.
Atresia of the external acoustic meatus in prehistoric populations
Authors: Hodges Denise C. , Harker Lee A. , Schermer Shirley J. 
Published: February 2006

AbstractA case of atresia of the external acoustic meatus is presented from a prehistoric Late Woodland site in Iowa. The affected individual was a female aged 30 to 40 years. The left temporal bone displayed a thin bony plate occluding the external acoustic canal. No evidence of middle ear or inner ear malformation was observed on the axial tomographs, although the external canal was shortened. The individual is diagnosed as having a mild case of congenital atresia. The report extends the geographical and temporal distributions of this archaeologically rare condition.
Paleoepidemiology of a Central California prehistoric population from CA‐ALA‐329: II. Degenerative disease
Authors: Jurmain Robert 
Published: February 2006

AbstractDegenerative lesions are scored and frequencies of involvement are computed for a skeletal collection from Ca‐Ala‐329, a prehistoric site on the southeastern side of San Francisco Bay, dating from 500 A.D. up to European contact. A large earthmound site, excavations conducted there by San Jose State University retrieved close to 300 burials. For this epidemiological analysis, reasonably complete and aged skeletons representing 77 adult females and 90 adult males are available. Degenerative changes are scored macroscopically in an ordinal fashion for the large fibro‐cartilagenous joints between adjacent vertebral bodies (vertebral osteophytosis) as well as the small apophyseal articulations of the spine. In addition, in the peripheral skeleton degenerative changes are scored in the temporo‐mandibular, shoulder, elbow, hip, and knee joints as well as the small articulations of the hands and feet. The most common degenerative changes in the spine are seen between the vertebral bodies of the lower lumbar region. In the peripheral skeleton the highest involvement of degenerative disease is seen in the hands and feet. Compared to other relevant osteological samples, this group of hunting‐gathering California Indians shows more degenerative changes than settled agriculturists (from Pecos Pueblo, New Mexico) but substantially less frequent involvement than in arctic hunters (Alaskan Eskimos).
Dermatoglyphics and anthropometric relationships within the Iñupiat (Eskimo) hand
Authors: Jamison Cheryl Sorenson , Jamison Paul L. , Meier Robert J. 
Published: February 2006

AbstractOn the basis of earlier findings with Easter Islanders suggesting a positive correlation between dermatoglyphic variables and hand anthropometric measurements, the present study was designed to determine if such a relationship could be generalized to another population, namely, Iñupiat (Eskimo). Since some dermatoglyphic and anthropometric variables were available for both sides of the body, the extension of this study to explore the question of asymmetry was also possible. The Iñupiat sample numbered 142 male and 176 female adult inhabitants of five Alaskan North Slope communities. The major findings of this study included, for males, significant negative correlations between left arm length and digital ridge counts and positive relationships between the palmar variable of axial index and hand length on both hands. For females, the hand breadth/length index was negatively related to most of the digital variables. Very little definitive information regarding the relationship of the asymmetry variables between the two types of measures was ascertained.
Size of the sella turcica and its relation to iron deficiency anemia: A prehistoric example
Authors: Fairgrieve Scott I. 
Published: February 2006

AbstractThis paper examines the usefulness of volume and area assessments of the sella turcica from radiographs in order to aid in the differential diagnosis of iron deficiency anemia in past populations. Lateral and posterior‐anterior radiographs were taken of each cranium in the sample. The length, depth, and width of the sella turcica were then measured directly from the appropriate view, and subsequently the volume and area were calculated for each. The 20–25 year‐old cohort was found to yield the most promising results; however, a statistical difference was not found to exist using the volume or area. The width dimension was found to be of far more use than any other in this study. In no instance was any feature of typical porotic hyperostosis, visually or radiographically, found to be statistically correlated with any difference in the dimensions of the sella turcica. A discussion of how the various dimensions of the sella turcica react to changes in size of the hypophysis cerebri is presented.
Continuous‐variable quantification of dermatoglyphic whorl patterns: A statistical study of angular measurements
Authors: Singh Chanchal , McKnight Karl B. 
Published: February 2006

AbstractCore(s) and triradii of dermatoglyphic whorl patterns were joined together to form triangles. Base angles of these triangles were measured (in degrees). The tangent angle at the lower edge of a ridge crossing the core—triradius line was also measured in degrees on each side of the whorl. Significant differences and similarities of these angles were investigated for unrelated Caucasian males and females by the use of Student's t‐ and Pearson's r‐tests. Angular findings were related to the corresponding information provided by ridge counts. Similarities and differences between males and females are described.
The choice of a statistic for testing hypotheses regarding seasonality
Authors: Reijneveld Sijmen A. 
Published: February 2006

AbstractThis paper discusses statistical methods for testing hypotheses of seasonality in births across one year, using monthly frequencies. It argues that the Freedman test, a variant of the Kolmogorov‐Smirnov one‐sample test, and the Edwards test and its modifications are most appropriate for this purpose. These tests take into account the order of the monthly frequencies and have a higher power than the oridinary chi‐square goodness‐of‐fit test, regarding seasonality. The paper addresses some points mentioned in earlier papers by McCullough, and O'Brien and Holbert.