Paper short abstract:

The incidence of caries and periodontitis were compared on the Jomon skeletal remains from two sites, Nakazuma shell-midden and mountainous inland Kitamura sites. Results suggest a different level of carbohydrate consumption and a plausible sexual division of dietary subsistence behavior.

Paper long abstract:

As for the prevalence of caries and periodontitis in Jomon people in Japan, previous studies have reported a relatively higher caries incidence (ca. 10% on average) compared to an average of prehistoric hunter-gatherers, and have estimated a widely prevailing affection of periodontal diseases for the Jomon population. However, we have now realized a wide variation in the caries incidence among sites of Jomon and a lack of tangible data of periodontitis for them. We present and compare here the prevalence of caries and periodontitis for two Jomon sites, Nakazuma shell-midden and mountainous inland Kitamura sites, where different environmental resources possibly affect a variety of subsistence patterns on diet. Results indicate that both caries and periodontitis are prevalent and the sex differences are significant in Nakazuma, while Kitamura site possesses low caries and high periodontitis rates with negligible sex differences. Although the caries and the periodontitis are both infectious via intraoral bacteria, the former is more linked to carbohydrate consumption in the diet. The results suggest that Nakazuma Jomon people might have a more carbohydrate diet than the Kitamura, and that the former society might form a level of sexual division in dietary collection, distribution and consumption behavior leading to the significant sex difference in the prevalence of caries and periodontitis.