@article{oai:rekihaku.repo.nii.ac.jp:00000428,
 author = {春成, 秀爾 and Harunari, Hideji},
 journal = {国立歴史民俗博物館研究報告, Bulletin of the National Museum of Japanese History},
 month = {Mar},
 note = {application/pdf, The custom of teeth filing consists in engraving two or three lines of grooves in human upper median incisors and one line of groove in the upper lateral incisor to work the teeth into forked form. This custom exsisted in Africa in 19th century, in the Central America from early Preclassic period (1400 B. C.) to Postclassic period (1500 A. D.) and in Japan in the latest Jomon period (1000-200 B. C.).
Specimens of teeth filing in Jomon period have been unearthened from 8 sites in Aichi Prefecture and Osaka Prefecture, both in Central Japan (28 samples in all). These 28 samples are divided into 13 males, 14 females and 1 unknown. The number of unearthened specimens is the highest in Ikawazu site (9 samples) and Yoshigo site (8 samples).
The teeth filing has been executed on about 20% of human adult bones unearthened at one site. Since the teeth filing is recognized also on the teeth of humans dead at their 15 to 16 and 19 to 20 years of age, it may assumed that almost all the filings were performed in their teens. Though some teeth filing remains inachieved on the teeth of humans at their 20s and 30s, we may presume that the filing was carried out in their teens too.
In this region, there unearthened two types of specimens of teeth  extraction: type 4I where two upper canines and four lower incisors have been extracted and type 2C where two upper canines and two lower canine teeth have been extracted. It is assumed that any adult belonged to either of these two. Examples of teeth filing are found 25 cases in type 4I, 2 cases in type 2C and only 1 case where any lower tooth except two upper canines has not been extracted (type 0). The teeth filing is onesidedly numerous in the type 4I. Further let us note that the human bones with waist ornaments belong, for the most part, to the 4I type. The author assumes that the humans belonging to the type 4I were those people who were from the region and lived in the settlement in that region even after their marriage and the type 2C, those who came from other settlements after their marriage.
It is supposed that the males and females with their teeth filed were basically from the region and considered as the closest blood relatives to the ancestors of the tribe in that region. They were of special lineage and their blood kinship might have been: mother-son, father-daughter, elder sister and younger brother, elder brother and younger sister, for example. With the relationship to their ancestors as their backbone of authority, they should have displayed to the full their power as political leaders and at the same time operated some tribal system together with the teeth-filed people belonging to other settlements.},
 pages = {87--140},
 title = {叉状研歯},
 volume = {21},
 year = {1989},
 yomi = {ハルナリ, ヒデジ}
}