This paper is concerned with the problem of the origin and the racial affiliation of recent Sakhalin Ainu, rather than with the well-known uniqueness of the cranial morphology of this population. In this study, odontometric and morphological observations were performed on the dentition of Sakhalin Ainu.
The overall tooth size of Sakhalin Ainu is quite small. In this respect, Sakhalin Ainu shares the similar characteristics with those of Hokkaido Ainu, the Neolithic Jomon population, some geographically isolated Japanese, and Negritos. As regards the shape factor of the dental measurements, on the other hand, Sakhalin Ainu shows the close affiliation to the typical Mongoloid populations such as Aleuts, Karluk (Alaska Eskimos), Chinese from the northern area of China and modern main island Japanese. Distance analysis based on the several non-metric crown features displays the intimate association of Sakhalin Ainu with Negritos and the populations who may have been derived directly from Southeast Asian Proto-Mongoloid population.
Taking these results into account, we cannot ignore some genetic influence of Northeast Asian populations on the physical characteristics of Sakhalin Ainu. However, the origin of this population may have been traced back to the Southeast Asian Proto-Mongoloid population. The dental evidence shown in this study may contribute to the establishment of biological relationships among Sakhalin Ainu and the neighboring populations.