J. Anthrop. Soc. Nippon人 類 誌 100(1):1-29(1992) Morphometrical and Dental Pathological Studies on Skulls from Yin-Shang Period Naohiko INOUE1), Yoshihiko TAKAHASHI1), Reiko SAKASHITA1), Ming-Li WU1), Tadashige NozAKlI1), Chi-Wen CHEN2), Tetsuya KAMEGAI3) and Koichi SHIONO4) 1) Department of Oral Surgery, Branch Hospital, The University of Tokyo 2) Union Dental Group, Taipei, Taiwan, Republic of China 3) Department of Orthodontics, Faculty of Dentistry, Iwate Medical College 4) Department of Pedodontics, Kagoshima University Dental School Abstract Three hundred and ninety eight skulls from the Yin-Shang period of China were investigated. The purpose of the present study is (1) to test inter-group difference in morphometrical characters since the samples were reported to be classified into several subgroups (YOUNG, 1985a, b); (2) to analyze the distribution pattern of dental disorders; (3) to find relationships between morphological characters and food culture. On the basis of preliminary examination, 186 male skulls from the six subgroups were selected for craniometric as well as roentgenographic cephalometric measurements and the examination of dental disorders. The results obtained are as follows: (1) statistically significant inter-group differences in morphometrics support YOUNG's initial classification of subgroups; (2) insignificant inter-group difference in dental disorders may suggest that there was no apparent dietary difference among subgroups; (3) it does not seem inducible that the dental disorders are modified by morphological characters; (4) a unique distribution pattern of dental caries in the subgroup II is likely to suggest life history different from those of the other subgroups; (5) the dominant reductive trend of lower face in the subgroup V may suggest their superiority in social status. Key Words Yin-Shang period, Skeletal remains, Craniometrics, Roentgenographic cephalometrics, Dental disorders Introduction sisted of 398 skulls which were excavated from In the spring of 1990, the present authors had Houchiachuang, Anyang, Henansheng, China, an opportunity to investigate skulls from the through an extensive and systematic project Yin-Shang period, a collection of the Institute of during the period from 1928 to 1937 by the History and Philology, Academia Sinica, the excavating party of the National Research Republic of China (Taiwan). This collection con- Institute of History and Philology. According to Article No. 9103 Received November 13, 1991 2 N. INOUE et al literature (XIA, 1985; LI, 1982, 1985; YOUNG, as analysis of anthropometrical data (LI, 1982). 1985a), they originally included thousands of Though the final consensus is not yet obtained, skulls as well as postcranial skeletons, among it is considered today that this skeletal popula- which there were many complete sets. However, tion consists of five anthropologically different more than a half of the skulls were either ruined races (YOUNG, 1985a): Group I - Classical through World War II or lost during the time of Mongoloid type; Group II - Oceanic Negroid repeated long distance conveyance following the type; Group III - Caucasoid type; Group IV - move of the Academia Sinica through Nanjing, Eskimoid type; and Group V - Morphologically Yunnansheng, Sichuansheng, and Nanjing again, unidentified type [Fig. 1 to Fig. 3 (upper)]. to avoid the disturbances of the war. Besides the traditional anthropometric method There were also lots of cultural remains such of studies, there is a new trend in which the as bronze ware, potteries, bone ware, gem ware, skeletons are archaeologically utilized as carriers ornaments of vehicles and horses, from which the of the records of culture and life history in the date of the ruins of Anyang was estimated to be past (KATAYAMA, 1990). Traits of dental 1,400-1,100 years B.C., or the later half of the pathological conditions seem to be the most Yin-Shang period. KAIZUKA(1974) described the enduring and informative ones among these history of the dating in detail, pointing out that archaeological data, because dental diseases are it was essentially significant that a large mass of strongly affected by the contemporary diet and "Jiaguwen" , inscription on bones and tortoise eating habits, and the tooth-to-denture-base carapaces, were decrypted and decored. Thus, the discrepancy resulting from cumulative effects of collection must be the oldest one certified by diet life in the preceding periods (INOUE et al., historical and archaeological evidences. 1986a). On the basis of these interrelations There were many riddles around these skulls between the dental disorders and diet, the present which have caused long controversies over the authors applied multivariate analysis to 17 composition of this skeletal population. One of morphological and dental pathological variables the most important themes seemed who and what from 18 skeletal populations from the early kind of race was the founder of the Yin-Shang Jomon to the Kofun periods in Japan, and found dynasty (YOUNG, 1985a). Derived from these that the dental disorders expressed the geo- questions, it was also a matter of interest whether graphical peculiarity of the groups, while the there were any people who were to be called tooth-to-denture-base discrepancy was subject to original Chinese, or they were just the eastern or their chronological period. From these facts, the western barbarians. According to YOUNG, present authors have deduced that the dispersal TURNER (1979) stated after a study on nonmetric of physical character and the diffusion of culture dental characters that they must be a homo- progress independently of each other, namely the geneous Mongoloid population. HOWELLS former goes on slowly and the latter advances (1979), on the basis of multivariate analysis using rapidly (INOUE et al., 1986b). craniofacial morphological data, also insisted on If the collection of skulls from the Yin-Shang the unity of the samples. In opposition to these period consisted of several different subgroups, opinions, YOUNG (1985b), COON (1958), and LI then it must be one of the rare cases in which (1982, 1985) advocated that the collection con- several ethnic groups existed at the same time and sisted of several different races on the basis of in the same area. In the present study, it was morphological comparison of the skulls as well attempted first to examine whether each sub- Skulls from Ying-Shang Period 3 group had sufficient basis to be approved of its ments projected on the median sagittal plane were independence, not to participate in the long measured on roentgenographic cephalograms. lasting discussion on the races constituting the However, the measurements of the cranial and collection. It was also intended to ascertain the facial breadths, cranial length, and the size of distribution of dental disorders resulting from the mandible were measured directly on skulls using cultural environment in different subgroups, and pelvimeter and sliding calipers. Measurements of to confirm the independency between dentofacial teeth were also carried out directly on skulls using morphology and culture. sliding calipers. Items of measurement were as described below. Materials and Methods 1) Direct measurements Materials Direct measurements on skulls were carried Materials used were 220 well preserved out for 11 items shown in Table 2. samples selected from 398 skulls from the Yin- 2) Indirect facial measurements on roentgeno- Shang period. For the purpose of discussing the graphic cephalograms inter-group difference of morphometrical and Roentgenographic cephalograms of skulls dental pathological data, the YOUNG's classifica- were taken by "Veraview" Roentgenographic tion was adopted [Figs. 1-3 (upper)]. In addi- Cephalo-Pantomostat (Morita Co.). The tion to his five groups, the remaining skulls [Fig. measurement was carried out indirectly on the 3 (lower)] were also used as the 6th group tracing films of cephalograph(INOUE andSUZUKI, according to the previous report (Institute of 1971) using the landmarks and reference lines as History and Institute of Archaeology, CASS, illustrated in Figs. 4 and 5, respectively. As shown 1985). in Table 3, the measuring items consist of 11 These materials consisted of 143 males, 16 linear (Fig. 6) and 18 angular (Fig. 7) measure- females, and 59 uncertain or unknown sex. ments (INOUE et al., 1982). In addition, 9 linear Because of the very low rate of females, and the and angular measurements (Fig. 8), which were largely different sex ratios among groups, the used for discriminant analysis in the previous inter-group comparison was carried out only for study of the present authors (INOUE et al.,1991), the males. For the purpose of obtaining enough were also employed in this study. sample numbers, re-classification of the group of 3) Measurement of teeth unknown sex was carried out using discriminant The mesio-distal and bucco-lingual crown analysis of roentgenographic cephalometric data diameters were measured on all the teeth, except (INOUE et al., 1991). The final number of for those showing tooth impaction, incomplete materials resulted from this procedure was 186 eruption, or severe attrition. as shown in Table 1. Table 1. Number of materials used Method of study Method of study mainly consisted of mor- phological measurement and examination of dental disorders. 1. Morphological measurement All the items of linear and angular measure- 4 N. INOUE et al. Fig. 1. Skulls from the Yin-Shang period: Group I (upper) and Group II (lower).