Ritual Tooth-Ablation in Doigahama Yayoi People

Abstract

The origin of the ritual tooth ablation of Doigahama Yayoi people has been long discussed since this problem is concerned with the question of the Yayoi people's origin in Northern Kyushu and Yamaguchi Prefecture. No definite answer, however, has yet been obtained, partially because of a deficiency in the data on ritual tooth ablation of this site.
One hundred and seven skulls, excavated from the Doigahama site during the 1st to 11th surveys, are examined here and compared with late Jomon and other Yayoi peoples. In Doigahama, the intentional extraction of one or more front teeth was found in 81 skulls (75.7%) which is a relatively high frequency among the Yayoi population, though it is lower than that of the Tsugumo, Yoshigo and Inariyama sites in the late Jomon period (nearly 100%, Table 2). There was also a sex difference observed for this frequency in Doigahama (male-64.2%, female-87.5%, Table 3).
Ritual tooth ablation found in Doigahama is characterized by the following points;
1. The main object of tooth extraction is canine, especially the upper canine, and about 80% of individuals have the traits of this practice. In this regard, there is a possibility that the Doigahama people engaged in the same tradition of the Jomon people, but the number of extracted canines in Doigahama, as well as the other Yayoi people, decreased to half or one-third of that in the Jomon people (Table 6). Furthermore, the canines of males were extracted unilaterally (right side in almost cases) and those of females were extracted bilaterally.
2. The upper lateral incisors were also frequently extracted (54%). The Yayoi peoples of Doigahama and Northern Kyushu are distinguished from Jomon and North-west Kyushu Yayoi in respect of the frequency of this type of tooth ablation (Table 8, Fig. 3).
3. Lower front teeth are seldom extracted in Doigahama and it provides an excellent comparison with the Jomon and North-west Yayoi people, which is characterized by a high frequency of extraction in the mandibular front teeth. The typical type of ablation of the Jomon people, in which all incisors in the mandible are extracted, does not exist in Doigahama. Sex difference was also observed in the frequency of lower tooth extraction among Yayoi people, especially in the North-west Yayoi people.
4. The ritual ablation practices of Doigahama were begun at 12-13 years of age (Table 9, Fig. 5).
As a whole, ritual tooth ablation in Doigahama shows a distinct difference as compared with that of the Jomon peoples, though some similarities were also revealed. The Yayoi people in north Kyushu show resemblances to the Doigahama in these points. On the other hand, the rituals of north-west Kyushu bear a certain similarity to the Jomon in their practice of teeth removal. Furthermore, the ancient Chinese may have something in common with the Doigahama, the practice in which are characterized by extraction with a strong bias for upper lateral incisors and by ascarcity of tooth extraction in the mandible.
According to these results, it would be unsuitable to say that the Yayoi people in Doigahama carried on the same tradition of ritual tooth ablation as the Jomon people, and the influence of other migrant populations from the Asian Continent would be a subject eminently worthy of further consideration.