Distribution of Tabercle-shaped Incisors in South Pacific Populations.

Abstract

The basal tubercle and its related traits on the basal part of the lingual surface of maxillary central incisors vary in developmental grades. Although a well-developed basal tubercle was observed in fossil humans, much attention to this trait has not been paid in modern humans. We compared five morphological traits on the lingual surface of maxillary incisors among seven Pacific populations. Results showed that the South-Pacific populations examined in this study especially Fijians and New Guinea Highlanders had a well-developed basal tubercle, but with a low frequency of shovel-shaped incisors. On the contrary, Japanese and Kiribatian populations of this study had a high frequency of shovel-shaped incisors, but a low frequency of tubercle-shaped incisors. It was suggested that the basal tubercle is one of the key dental traits in characterizing Pacific populations.