Bull. Natl. Mus. Nat. Sci., Ser. D, 39, pp. 9–18, November 22, 2013

Secular Changes in Craniofacial Morphology during
the Edo Period of Japan
Kazuhiro Sakaue
Department of Anthropology, National Museum of Nature and Science
4–1–1 Amakubo, Tsukuba-city, Ibaraki Prefecture 300–0005, Japan
Telephone: ＋81–29–851–8187, Fax: ＋81–29–853–8998
E-mail: k-sakaue@kahaku.go.jp

Abstract Although signiﬁcant differences in craniofacial morphology can be recognized among
the townsmen, the lower-middle-class samurai, and the higher-class samurai (including shogunʼs
wives and territorial lords) from the middle-late Edo period (Sakaue, 2012), there has been no
study on secular changes in craniofacial morphology during the Edo era. The purpose of this study
is to investigate the morphological differences in the skull between the early Edo period and the
middle-late Edo period. The subjects included 44 males and 22 females from the early Edo period,and 181 males and 118 females from the middle-late Edo period. A total of 67 measurements were
examined, and multivariate analyses were employed to test the signiﬁcant differences between theearly Edo period skulls and the middle-late Edo period skulls. The results showed that the cranial
morphology of the early Edo period was similar to that of the middle-late Edo period townsmen,
but apparently different from that of the middle-late Edo period samurai of both sexes. The early
Edo period subjects had somewhat stouter mandibles than those of the middle-late Edo period
male townsmen and relatively larger skulls than those of the middle-late Edo period female townsmen. Thus it can be said that secular changes in cranial morphology occurred during the Edo
period.
Key words : Edo, Skull, Craniofacial morphology, Secular change

Introduction
In a previous study, group differences in craniofacial morphology could be recognized statistically between the skeletal remains buried in circular wooden cofﬁns “Hayaoke” and those buriedin ceramic cofﬁns “Kamekan” during the middle
to late Edo period (from the late 17th century to
the late 19th century) (Sakaue, 2012). Because
the “Hayaoke” was utilized by the townsmen andthe “Kamekan” by the lower-middle-class samurai, it could be said that oneʼs craniofacial morphology was affected by oneʼs social class among
the Edo period people. These differences amongsocial classes can be investigated by using theskeletal remains after the late 17th century
because the “Kamekan” burial style commenced
after that time (Tanigawa, 2004).
In order to answer the question of why thesemorphological changes occurred, it will be helpful to know the time when the people in thesamurai class acquired the unique features ofthe skull. However, there has been no study on
secular changes in craniofacial morphology
during the Edo era. The large number of skeletal
remains newly excavated from the early Edo
period (the 17th century) makes it presently
possible to investigate this secular change.
Thus, the purpose of this study was to investigate the morphological differences in the skull
between the early Edo period and the middle-late
Edo period.
Materials and Methods
The materials of this study were composed ofhuman skeletal remains excavated from threecemetery sites located in Tokyo (Table 1). The

10Kazuhiro Sakaue
Table 1.
site

Early Edo
Hatchobori-Sanchyome (1st)Hatchobori-Sanchyome (2nd)
Shitaya-Dohochyo
Hitotsubashi Senior High Schoolsum
Middle-late Edo

Sites and sample sizes used in this study.

location

periodMale

FemaleChuou-ku
Chuou-ku
Taitou-ku
Chiyoda-ku

the last 16th A.D. to the middle17th A.D.
the last 16th A.D. to the middle17th A.D.
the last 16th A.D. to the late 17th A.D.
the last 16th A.D. to the late 17th A.D.

2
15
1
26
44
181

2
9
4
7
22
118

excavation results, historical records, and oldmaps of the Edo indicated that all temples ofthese cemeteries had been relocated to the otherplaces during the 17th century. Although most of
the skeletal remains excavated at these cemeteries are thought to be those of townsmen, somepeople of the samurai class may have been alsoburied at these cemeteries judging from epitaphs
and burial accessories, such as weapons (Toritu
Hitotsubashi koukou Iseki Chosa-dan, 1985;
Hatchobori Sanchome iseki (dainiji) Chosa-kai,2003).
The criteria for selecting the samples were as
follows: 1) complete closure of the sphenooccipital synchondrosis; 2) at least one remaining toothor socket of the maxillary central incisors; 3) atleast one remaining tooth or socket of molars foreach maxilla and mandible; 4) no contamination
by another individual or, if any, restricted contamination easily identiﬁable of another individual; and 5) almost a complete skull without
deformation or missing values for all measurements.
The sexual assessment of individuals was basically carried out with craniofacial traits (Sakaue
and Adachi, 2009). When these traits were insufﬁcient for identiﬁcation of the sex, some pelvic
features, such as a greater sciatic notch, ventral
arc, or ischiopubic proportion, were used (Bruzek, 2002). A total of 67 measurements were
examined (Table 2), and their deﬁnitions followed those of Martinʼs measurements (Baba,
1991). When both sides were available, the left
side was basically measured.
Statistical analyses were performed as follows:
1) The Shapiro-Wilk test was conducted for all
variables in each group in order to test for any

deviations from a normal distribution; 2) In order
to compare the relative signiﬁcance of differences between the early Edo period group andthe middle-late “Hayaoke” Edo period group or
between the early Edo period group and the middle-late Edo “Kamekan” period groups, the Dunnettʼs tests were conducted for variables of normal distributions, or the Steelʼs tests were carriedout for variables of doubtful normal distributions
as a multiple comparison procedure (Nagata andYoshida, 1997) ; 3) Forty-seven variables which
had been chosen in the previous study (Sakaue,2012) were also used for multivariate analysis in
this study. In addition, Wilksʼ lambdas were calculated and their statistical signiﬁcances were
tested in order to test the differences of thesegroups for a combination of dependent variables;4) The plot of factor scores were made in order
to elucidate group differences in cranial variationof the early Edo period people and the middlelate Edo period people. The principal componentscores of the early Edo period people were calculated by the component coefﬁcients resulting
from the principal component analysis on correlation matrix in the middle-late Edo period samples (Sakaue, 2012); and 5) The principal component analysis on correlation matrix was carriedout with 12 variables of the mandibular bone,which showed distinct differences between theearly Edo period people and the middle-late Edo
period people of both sexes. This analysis was
conducted on the middle-late Edo period people,
and then the scores of the early Edo period people were calculated by its component coefﬁcients. All statistical analyses were carried out
with SYSTAT 13.

Secular Changes in the Skull during the Edo Period
Table. 2

Summary statistics of all measurements and Indexes
Male

MartinNo.

Variables

11

Early
(N＝44)

Middle-late(Hayaoke)(N＝131)

FemaleMiddle-late(Kamekan)(N＝50)

Mean S.D. Test Mean S.D. Test Mean S.D.
1 Maximum length
181.8 6.7
8 Maximum breadth
138.3 5.1
17 Basion-Bregma height
137.1 4.9
9 Least frontal breadth
93.4 4.7
10 Maximum frontal breadth
115.4 3.9
5 Basion-Nasion length
101.9 3.5
11 Biauricular breadth
125.3 4.4
12 Biasterionic breadth
108.9 3.9
13 Mastoid width
103.3 4.5
40 Basion-Prosthion length
98.7 4.6
14 Minimum cranial breadth
67.9 3.0
7 Foramen magnum length
35.6 2.1
16 Foramen magnum breadth29.2 1.6
516.5 16.6
23 Horizontal circumference
24 Transverse arc
313.1 9.5
26 Frontal sagittal arc
127.5 5.6
27 Parietal sagittal arc
126.2 6.9
28 Occipital sagittal arc
116.6 6.1
25 Total sagittal arc
370.3 12.2
29 Frontal sagittal chord
111.7 4.3
30 Parietal sagittal chord
113.2 5.5
31 Occipital sagittal chord
98.3 4.2
43 Outer biorbital breadth
104.6 3.6
43a Bifrontal breadth97.5 3.8
Nasion subtence (calculated)
14.5 2.1
44 Biorbital breadth
98.5 3.7
45 Bizygomatic breadth
134.8 4.3
46 Bimaxillary breadth (zm)
99.8 5.2
46b Bimaxillary breadth (zm:a)100.3 5.4
Subspinale subtence (calculated) 22.3 2.9
48 Upper facial height71.9 3.8
48H Upper facial height (Howells)
68.1 3.5
48d Malar height
23.7 2.4
49a Interorbital breadth
21.2 1.8
50 Anterior interorbital breadth
16.9 2.1
51 Orbital breadth
43.0 1.9
52 Orbital height33.9 1.9
54 nasal breadth
24.9 1.6
55 nasal height51.9 2.855(1) Height of piriform aperture
30.2 2.9
56 Length of nasal bone
23.8 3.1
57(1) Maximum breadth of nasal bone 17.9 1.8
57 Least nasal breadth
7.1 1.9
Nasal subtense (calculated)
2.2 0.9
60 External palate length
51.6 3.7
61 External palate breadth64.9 3.8
62 Internal palate length44.6 2.7
63 Internal palate breadth40.7 2.7
66 Bigonial breadth
102.6 5.8
68 Projective length of mandible
72.1 4.9
65 Bicondylar breadth
120.7 5.565(1) Bicoronoid breadth97.3 5.5
67 Bimental breadth
47.7 3.0
69 Height of mandibular symphysis 35.0 3.6
69(1) Mandibular body height
31.4 2.3
69(2) Mandibular body height at M2 27.0 2.0
69(3) Mandibular body breadth
13.8 1.5
69b Mandibular body breadth at M2 18.0 1.5
70 Height of mandibular ramus
63.6 4.971a Minimum width of ramus
34.7 2.971(1) Condylo-cornoid breadth
35.5 3.9
Mandibular condyle breadth20.2 1.8

181.5 6.4
138.5 4.5
136.2 4.7
93.5 4.2
114.7 4.2
101.8 4.5
126.0 4.3
108.5 4.6
103.2 4.7
99.3 4.9
68.7 3.5
35.8 2.2
29.6 2.0
518.2 13.9
312.8 9.4
125.9 5.7
126.3 8.1
118.2 8.3
370.4 13.3
110.6 4.4
112.7 6.4
98.4 5.3
104.7 4.0
97.3 4.0
14.1 2.4
97.9 3.8
134.9 4.5
99.9 4.7
99.9 4.7
22.7 3.3
72.2 4.2
68.3 4.0
24.3 2.5
21.0 2.0
16.9 2.1
43.3 2.0
34.1 1.9＜ 25.6 1.9
52.3 3.1
29.6 2.6
24.4 2.8
18.2 1.9
7.3 1.6
2.5 1.0
52.3 3.0
65.7 3.8
45.5 2.7
40.7 3.3＞ 100.2 5.8
70.7 5.0
121.6 5.7
97.4 4.8
47.5 2.5
35.6 3.2
31.6 2.7
26.8 2.5≫ 13.2 1.4≫ 17.1 1.6＜ 64.9 4.4
34.7 3.3
36.2 3.2
20.7 2.0

Early(N＝22)

Middle-late(Hayaoke)(N＝70)

Middle-late(Kamekan)(N＝48)

Mean S.D. Test Mean S.D. Test Mean S.D.

≫ 177.4 6.1 174.5 4.7≪ 141.3 5.3 135.0 5.8
138.0 5.7 129.5 4.3
94.4 4.9
90.5 3.8＜ 117.2 5.4 111.8 4.7＞ 99.9 4.2
95.3 3.0
125.0 4.3 120.2 4.7
108.2 5.2 106.7 4.0
102.2 4.8
98.3 5.0＞ 96.0 6.0
93.8 4.2≪ 69.7 4.0
65.0 2.5
35.3 2.4
33.7 1.9
29.9 2.2
28.5 2.0
514.9 13.0 502.7 12.8
≪ 321.0 11.7 301.8 10.7
126.9 5.3 121.6 5.0
125.7 8.3 120.6 8.6
117.7 5.4 116.4 8.5
370.2 12.5 358.6 12.3
110.8 4.4 106.6 3.4
112.2 6.5 109.9 6.0
99.3 4.1
97.5 5.3
104.0 4.0 100.5 3.0
96.8 3.7
93.4 2.8
14.5 3.1
12.7 1.4
97.3 3.7
95.3 3.1
133.1 5.1 126.6 4.2＞ 97.3 5.0
94.7 4.1＞ 97.6 4.9
95.2 4.7＜ 23.9 2.919.5 2.8＜ 73.7 3.3
66.4 4.1＜ 69.9 3.2
62.9 3.9
23.7 2.5
22.1 1.9
20.7 2.1
20.8 1.7
16.9 2.1
16.8 1.7
43.4 1.8
41.1 1.8≪ 35.6 1.9
33.1 1.9
24.5 1.7
24.2 1.3≪ 53.6 2.6
47.5 2.9
30.7 2.5
26.1 2.4
24.9 3.0
22.4 2.4
17.7 1.6
17.5 1.5
7.2 2.0
7.6 1.6＜
2.6 1.1
1.8 0.9
50.4 3.5
49.0 2.5
65.5 3.8
61.5 3.8
44.7 2.7
42.4 2.5＞ 39.5 3.3
39.4 3.0≫ 98.9 5.995.2 5.4
69.8 4.9
67.0 3.5
120.8 5.8 116.1 5.1
98.1 5.2
94.4 4.1
47.4 2.5
46.5 2.7
30.5 3.4
36.0 3.1
32.1 2.4
28.9 2.8
26.5 2.7
25.1 2.3≫ 12.5 1.4
13.3 1.4≫ 16.6 1.3
17.1 1.1
64.8 4.3
57.9 3.4≫ 32.4 2.6
33.2 2.2＞ 33.4 3.9
32.8 2.4
20.6 1.9
18.5 1.8

172.3 6.7
133.2 5.7
130.6 3.9
89.3 4.8＞ 109.4 4.8
94.9 3.7
119.2 4.4
＞ 104.4 4.0
97.2 5.9
94.4 5.3
64.1 3.3
33.7 2.0
28.3 1.7＞ 494.6 14.0
301.7 11.3
121.3 5.9
120.9 7.1
115.1 8.1
357.3 12.9
106.3 4.2
108.9 5.7
96.8 5.4
99.2 3.7
92.3 3.6
12.5 2.3＞ 93.6 3.5
125.0 3.8
93.3 3.8
94.1 4.2
20.5 3.0
66.7 4.2
63.4 4.4
22.0 2.0
20.3 2.1
16.4 1.9
40.8 1.9
33.3 1.8
24.4 1.6
48.5 2.7
26.5 2.2
22.6 2.5
16.9 1.6
7.0 1.9
1.8 0.9
50.3 3.6
61.4 3.4＜ 44.0 2.7
38.1 2.6
93.8 5.6
66.2 4.3
113.8 5.2
≫ 90.5 4.5
45.8 2.2
31.6 3.2
28.7 2.5
24.8 2.2
12.7 1.2
17.0 1.4
57.6 3.9
33.1 2.7＜ 34.1 3.0
18.5 1.7≫

169.1 5.5
135.3 4.4
＜ 132.0 4.0
89.5 3.3
110.1 3.9
95.1 3.6
118.8 4.6
＞ 104.2 3.8
96.4 4.3
92.7 3.8
65.1 3.7
33.7 2.0
28.1 1.9≫ 491.1 11.9
304.6 9.9
119.8 5.7
119.8 11.1
113.9 6.6
353.4 13.0
105.6 4.2
＞ 106.5 7.0
97.6 4.2＞
98.7 3.0
92.1 2.8
13.1 2.3≫
92.8 3.1＞ 123.8 4.6＞
92.2 4.8
92.7 4.9≪
22.0 2.3＜
68.5 3.4＜
65.1 3.6
21.9 1.9＞
19.7 2.0
16.3 1.7
41.2 1.5≪
34.6 1.7
24.5 1.9＜
49.4 2.6＜
27.5 2.7
22.9 2.8
17.1 1.9
7.8 1.6＜
2.3 0.9
48.9 2.3
61.5 3.6
43.4 2.1
38.6 3.0≫
90.9 4.5
65.6 4.3≫ 110.8 5.8≫
90.5 5.0
45.2 2.0＜
32.2 2.8
28.9 2.1
24.3 2.0≫
12.2 1.1＞
16.3 1.5
57.6 3.9≫
31.2 2.4
32.7 2.9
17.9 1.4

12Kazuhiro Sakaue
Table. 2

Continued

Male
MartinNo.

Variables

Early(N＝44)

Middle-late(Hayaoke)(N＝131)

FemaleMiddle-late(Kamekan)(N＝50)

Mean S.D. Test Mean S.D. Test Mean S.D.
8/1 Cranial index
17/1 Index
17/8 Index
9/10 Index
9/8 Index
8/12 Index
40/5 Index
16/7 Index
27/26 Index
28/26 Index
29/26 Index
30/27 Index
31/28 Index(1＋8 Modulus＋17)/3 Frontal index of ﬂatness
Zygomatic index of ﬂatness
43/8 Index
46/45 Index
48/45 Index
48/46 Index
9/45 Index
45/8 Index
50/44 Index
52/51 Index
54/55 Index
54/55(1) Index
Simotic index
57/57(1) Index
61/60 Index
63/62 Index
68/65 Index
69(3)/ Index69(1)69b/ Index69(2)71/70 Index
72 Total proﬁle angle
73 Nasal prof ile angle
74 Alveolar proﬁle angle
75 Proﬁle angle of nasal bone
79 Mandibular angle

0.76 0.04
0.75 0.03
0.99 0.04
0.81 0.04
0.68 0.04
1.27 0.06
0.97 0.04
0.82 0.06
0.99 0.06
0.92 0.05
0.88 0.01
0.90 0.02
0.84 0.02
152.39 3.71
0.15 0.02
0.22 0.03
0.76 0.04
0.74 0.03
0.53 0.03
0.72 0.04
0.69 0.04
0.98 0.04
0.17 0.02
0.79 0.05
0.48 0.04
0.83 0.10
0.32 0.13
0.40 0.10
1.26 0.11
0.92 0.08
0.60 0.05
0.44 0.06
0.67 0.06
0.55 0.06
83.6 3.2
93.0 2.8
66.4 5.1
64.8 5.7
124.0 6.2

Early
(N＝22)

Middle-late(Hayaoke)(N＝70)

Middle-late(Kamekan)(N＝48)

Mean S.D. Test Mean S.D. Test Mean S.D.

≪
≪

≪
≪

0.77 0.05
0.76 0.03
0.98 0.05
0.82 0.04
0.67 0.04
1.28 0.06
0.99 0.04
0.84 0.05
1.00 0.07
0.95 0.08
0.88 0.02
0.90 0.02
0.84 0.03
145.35 3.59
0.13 0.02
0.22 0.03
0.75 0.04
0.75 0.03
0.53 0.03
0.72 0.05
0.71 0.03
0.94 0.04
0.17 0.02
0.82 0.04
0.51 0.04
0.93 0.09
0.25 0.12
0.41 0.10
1.22 0.09≫
0.87 0.07
0.58 0.05
0.44 0.04

0.80 0.03
0.78 0.03
0.98 0.03
0.81 0.03
0.66 0.03＜
1.30 0.05
0.98 0.03
0.84 0.05
1.00 0.09
0.95 0.08
0.88 0.02
0.89 0.04≪
0.86 0.02
145.49 3.37
0.14 0.02≪
0.24 0.03＞
0.73 0.03
0.74 0.03≪
0.55 0.03≪
0.75 0.05
0.72 0.03＞
0.92 0.03
0.18 0.02＜
0.84 0.05＞
0.50 0.04
0.90 0.13＜
0.29 0.11
0.46 0.09
1.26 0.09
0.89 0.08
0.59 0.04≫
0.42 0.04

0.69 0.08

0.69 0.07

0.68 0.09

0.57 0.05
0.50 0.05
84.4 3.6
82.9 2.8
92.8 4.0
91.8 2.3
67.5 6.7
63.9 4.7＞ 62.2 5.5
68.4 4.9＜ 126.5 6.9 123.7 4.9

0.58 0.06
81.3 3.4
89.1 5.8
62.8 6.2≫ 65.1 5.1＜ 126.5 6.8

0.76 0.03
0.75 0.03
0.98 0.04
0.82 0.03
0.68 0.03
1.28 0.05
0.98 0.04
0.83 0.06
1.00 0.07
0.94 0.08
0.88 0.02
0.89 0.02＞
0.83 0.03
152.03 3.54
0.14 0.02
0.23 0.03
0.76 0.03
0.74 0.03
0.54 0.03
0.72 0.04
0.69 0.03
0.97 0.04
0.17 0.02
0.79 0.04
0.49 0.04＜
0.87 0.10
0.34 0.12
0.40 0.09
1.26 0.08
0.90 0.08＞
0.58 0.04＞
0.42 0.05

0.80 0.04
0.77 0.03
0.78 0.03
0.74 0.03
0.98 0.04
0.96 0.04
0.81 0.03
0.81 0.03
0.67 0.04
0.67 0.03≪
1.31 0.06
1.27 0.06
0.96 0.05
0.98 0.04＜
0.85 0.06
0.85 0.05
0.99 0.07
0.99 0.08
0.93 0.06
0.96 0.07
0.87 0.02
0.88 0.01
0.89 0.03
0.91 0.05
0.84 0.02
0.84 0.02
152.24 4.09 146.32 3.52
0.15 0.03
0.14 0.01≪
0.25 0.03
0.21 0.03≫
0.74 0.03
0.75 0.03
0.73 0.03
0.75 0.03≪
0.55 0.03
0.52 0.04≪
0.76 0.04
0.70 0.06＜
0.71 0.03
0.72 0.03≫
0.94 0.04
0.94 0.04
0.17 0.02
0.18 0.02≪
0.82 0.05
0.81 0.05≫
0.46 0.03
0.51 0.03
0.80 0.08
0.93 0.08＜
0.37 0.13
0.23 0.11
0.41 0.11
0.44 0.10
1.30 0.10
1.26 0.10＞
0.87 0.16
0.93 0.09
0.58 0.05
0.58 0.04≫
0.39 0.05
0.46 0.05＞

0.64 0.07≫

0.54 0.05
83.3 3.1
92.4 3.1
64.8 6.3
63.4 6.0
124.5 6.9≫

0.63 0.08

＜

＞
≫

＞

≫
≪

0.54 0.05
82.7 2.5
91.8 3.0
64.3 5.2
64.7 5.0
129.6 7.2“＜” and “＜＜” mean the results of the Dunnettʼs test or the Steelʼs test for multiple comparison between “Early
Edo” group and “Hayaoke” or “Kamekan” respectively“＜” means P＜0.05 and “＜＜” means P＜0.01 respectively.
The means with under bar indicate that the normal distribution of its variable is denied with the Sapiro-Wilk test.
The signs of inequality with under bar indicate that these tests were performed by the Steelʼs test.

Results
Table 2 shows the descriptive statistics of cranial variables of the early Edo period people, themiddle-late Edo period people buried in “Hayaoke” (the townsmen), and the middle-late Edo
period people buried in “Kamekan” (the lowermiddle-class samurai). Figure 1 shows the relative deviation curve of all liner variables basedon means of the early Edo period people. In

males, only 5 variables showed statistically signiﬁcant differences between the early Edo period
people and the middle-late “Hayaoke” Edo period
people, and 4 of the 5 variables were related tothe mandible (bigonial breadth, two mandibularbody breadths, and height of mandibular ramus).
On the contrary, there are 21 variables showing
statistically signiﬁcant differences between theearly Edo period people and the middle-late“Kamekan” Edo period people. These variables

Secular Changes in the Skull during the Edo Period

Fig. 1.

13

The relative deviation curve of all liner variables based on means of the early Edo period.

were almost the same as those showing statistically signiﬁcant differences between the “Hayaoke” group and “Kamekan” group (Sakaue,2012). In females, 7 variables (maximum frontal
breadth, biasteric breadth, horizontal circumference, biorbital breadth, internal palate length,
bicoronoid breadth, and condylo-cornoid
breadth) showed statistically signiﬁcant differences between the early Edo period people andthe middle-late “Hayaoke” Edo period people. As
seen in Figure 1, many variables of the early Edo
period people (47 out of 62 variables) tend to belarger than those of the middle-late “Hayaoke”
Edo period females. Likewise in males, the variables showing statistically signiﬁcant differences

Table 3. Results of Wilkʼs lambda between theearly Edo and the middle-late “Hayaoke” Edo or
the middle-late “Kamekan” Edo
MaleWilksʼ λp-Value

FemaleHayaoke Kamekan

Hayaoke Kamekan

0.586
0.002

0.406
0.130

0.270
0.001

0.113
0.000

between the early Edo period people and the
middle-late “Kamekan” Edo period people
resembled those between the “Hayaoke” groupand “Kamekan” group.
The Wilksʼ lambdas and their probabilities are
in Table 3. Statistically signiﬁcant differences of
the 47 variables existed between the early Edo

14

Kazuhiro Sakaue

period people and the middle-late “Hayaoke”
Edo period males, and between the early Edo
period people and the middle-late “Kamekan”
Edo period people of both sexes, but there wereno statistically signiﬁcant differences between
the early Edo period people and the middle-late“Hayaoke” Edo period females.
The scatter plots of the second and third principal component scores are presented in Figure 2
for males and Figure 3 for females. In this analysis, the second principal component was interpreted as the relationship among calvarial
breadth, orbital height, and sagittal diameter ofthe facial structure, and the third principal component was interpreted as the relationship among
facial ﬂatness and the heights of the orbit andnose (Sakaue, 2012). The letters in these plots
correspond to the photographs in Figure 4 formales and Figure 5 for females. In these plots,

Fig. 2. Plot of the second and third principal component scores of males.
The ellipses represent the 68.27% conﬁdence
interval for the early Edo period (thick line), themiddle-late “Hayaoke” Edo period (thin line),
and the middle-late “Kamekan” Edo period(dash line). The letters in the plot correspond to
those of Figure 4. “E”, “H”, and “K” correspondto “Early Edo”, “Hayaoke”, and “Kamekan”,
respectively. The measurements of the higherclass samurai (Daimyo) were done with elaborative casts (Sakaue, 2012).

most of the early Edo period people are scattered
within the standard deviation ellipse of the
middle-late “Hayaoke” Edo period people ofboth sexes. Therefore, it was difﬁcult to classify
the early Edo period people and the middlelate “Hayaoke” Edo period people with these characteristics; conversely, the “Hayaoke” group, the“Kamekan” group, and the higher-class samuraigroup (including shogunʼs wives “Ooku” and territorial lords “Daimyo”) of the middle-late Edo
period were easily classiﬁable.
Table 4 shows the results of the principal component analysis with 12 mandibular variables of
middle-late Edo period males. The ﬁrst principal
component, accounting for 29.1% of the total
variance, has relatively high loading values for
all measurements. Therefore, this component canbe interpreted as indicating total mandibular size.
The second principal component can be interpreted as indicating the relationship between
mandibular breadth and mandibular size in sagit-

Fig. 3. Plot of the second and third principal component scores of females.
The ellipses represent the 68.27% conﬁdence
interval for the early Edo period (thick line), themiddle-late “Hayaoke” Edo period (thin line),
and the middle-late “Kamekan” Edo period(dash line). The letters in the plot correspond to
those of Figure 5. The measurements of thehigher-class samurai (Ooku) were done withelaborative casts (Sakaue, 2012).

Secular Changes in the Skull during the Edo Period

15

Fig. 4. Male examples of each group. The letters correspond to those of Figure 1. “E” corresponds to early Edo
period, “H” corresponds to middle-late “Hayaoke” Edo period, and “K” corresponds to middle-late “Kamekan”
Edo period. The numbers after letters within ellipses correspond to the following: “1” is “having features of asamurai; “2” is “the closest to the centroid of ellipse”; “3” is “having features of a townsman”

tal direction. The third principal component canbe interpreted as mandibular body size. Table 5shows the results of the principal component
analysis with 12 mandibular variables of middlelate Edo period females. As in males, the ﬁrst
principal component can be seen as the total sizeof the mandible. For the second principal component, the breadth between coronoid processes
correlates with the variables mandibular bodyheight and sagittal diameter of the mandible. The
third principal component can be interpreted asindicating the relationship between mandibularbody size and mandibular breadth.
The scatter plots of the ﬁrst and third principal
component scores of mandibular variables arepresented in Figure 6 for males and Figure 7 forfemales. Component scores of the early Edo
period people were calculated by their coefﬁcients. In these plots, the distributions of thesamples of each group may indicate the morphological cline from the early Edo period specimens to the “higher class” specimens (“star” inthese plots) with some overlapping in both sexes.
This result indicates that the whole size of themandible and mandibular body size may show
secular changes from the early Edo period to the
middle-late Edo period.
Discussion
This study revealed that the craniofacial morphology of the early Edo period is similar to thatof the middle-late “Hayaoke” Edo period, but
apparently different from that of the middle-late“Kamekan” Edo period in both sexes. In addition,
the early Edo period people had somewhat
stouter mandibles than the middle-late “Hayaoke” Edo period males, and the early Edo period

16Kazuhiro Sakaue

Fig. 5. Female examples of each group. The letters correspond to those of Figure 1. “E” corresponds to early Edo
period, “H” corresponds to middle-late “Hayaoke” Edo period, and “K” corresponds to middle-late “Kamekan”
Edo period.
The numbers after letters within ellipses correspond to the following: “1” is “having features of a samurai; “2”is “the closest to the centroid of ellipse”; “3” is “having features of a townsman”
Table 4.

Results of princiapal component analysis with 12 mandibular variables of the middle-late Edo male.

Martin No.

Variables

1

2

3

4

66
68
65
65(1)
67
69
69(1)
69(3)
70
71a
71(1)

Bigonial breadth
Projective length of mandible
Bicondylar breadth
Bicoronoid breadth
Bimental breadth
Height of mandibular symphysis
Mandibular body height
Mandibular body breadth
Height of mandibular ramus
Minimum width of ramus
Condylo-cornoid breadth
Mandibular condyle breadth
Eigenvalues
Percent of explained (%)

0.495
0.609
0.620
0.406
0.581
0.410
0.531
0.420
0.523
0.684
0.506
0.601
3.49
29.1

0.385
−0.220
0.518
0.725
0.085
−0.202−0.228−0.3740.032−0.443−0.501
0.298
1.77
14.7

0.276
−0.0570.103−0.0480.136−0.728−0.6580.474−0.252
0.331
0.237
0.014
1.53
12.7

0.277
0.037
−0.228
0.152
0.598
0.263
0.105
0.340
−0.376−0.066−0.386−0.495
1.25
10.4

A bold number means its loading score is greater than 0.3

people had relatively larger skulls than the middlelate “Hayaoke” Edo period females. Thus it canbe said that secular changes in cranial morphol-ogy occurred during the Edo period.
It is interesting that craniofacial morphology
can change during such a short period of time.

Secular Changes in the Skull during the Edo Period
Table 5.

17

Results of princiapal component analysis with 12 mandibular variables of the middle-late Edo female.

Martin No.

Variables

1

2

3

4

66
68
65
65(1)
67
69
69(1)
69(3)
70
71a
71(1)

Bigonial breadth
Projective length of mandible
Bicondylar breadth
Bicoronoid breadth
Bimental breadth
Height of mandibular symphysis
Mandibular body height
Mandibular body breadth
Height of mandibular ramus
Minimum width of ramus
Condylo-cornoid breadth
Mandibular condyle breadth
Eigenvalues
Percent of explained (%)

0.522
0.568
0.699
0.465
0.495
0.197
0.442
0.495
0.427
0.607
0.464
0.529
3.07
25.6

0.347
−0.371
0.099
0.544
0.161
0.519
0.434
−0.0840.213−0.578−0.634−0.1351.85
15.4−0.3670.122−0.449−0.355−0.082
0.653
0.650
0.339
0.174
0.207
0.239
−0.4771.81
15.0−0.081−0.2260.263
0.043−0.7370.184
0.222−0.4160.178−0.018
0.341
0.338
1.19
9.9

A bold number means its loading score is greater than 0.3

Fig. 6. Plot of the ﬁrst and third principal component scores of male mandible.
The ellipses represent the 68.27% conﬁdence
interval for the early Edo period (thick line),
the middle-late “Hayaoke” Edo period (thinline), and the middle-late “Kamekan” Edo
period (dash line).

Fig. 7. Plot of the ﬁrst and third principal component scores of female mandible.
The ellipses represent the 68.27% conﬁdence
interval for the early Edo period (thick line), themiddle-late “Hayaoke” Edo period (thin line),
and the middle-late “Kamekan” Edo period(dash line).

During the 17th century, Edo city underwent
drastic changes in terms economics, logistics,
labor characteristics, culture, and demographics(Kito, 2010). These changes affected the lifestyles of the common people, which might have
led to variations in the morphological structureof the mandible and cranium among the Edopeople.

It is questionable whether the morphologicaldifferences between the early Edo period and the
middle-late “Kamekan” Edo period can be
regarded as secular change. These differences
may only reﬂect differences in social class, and it
is difﬁcult to determine what social class a person of the early Edo period belonged to. Unfortunately, there is presently no reliable way to deter-

18

Kazuhiro Sakaue

mine the social class from the burial method oraccessories of the early Edo period. The social
status of the temple where the cemetery is
located might be helpful in roughly estimating
the social class of the buried people at a particular archaeological site. More samples and a new
method for determining social class are neededin future studies.
Acknowledgement
I wish to thank Dr. K. Hirata, Professor of the
Department of Anatomy, St. Marianna University
School of Medicine, for kindly permitted us to
study the skeletal remains. I wish to express mysincere gratitude to Dr. Y. Mizoguchi, Director of
the Department of Anthropology, the National
Museum of Nature and Science, and Dr. Sawada(St. Marianna University School of Medicine)for their many helpful suggestions in this study.
My sincere thanks are due to Ms. M.
Kajigayama, Ms. A. Nakatuka (The National
Museum of Nature and Science), and H. Koizumi (Tokyo Metropolitan Board of Education)
for their valuable advice. This research is supported by JSPS KAKENHI Grand Number
23370102.

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