宮古島ならびに石垣島住民の歯の形質人類学的研究 : 臼歯の大きさ

Abstract

The dentition of the Ryukyu islanders were metrically examined in terms of inter island variation and biological population affinity. Measurements were of the crown diameter from first premolar to second molar in 144 plaster casts on Miyakojima population and 322 on Ishigakijima. Measuremants were statestically compared between two populations. The upper and lower first molars are the largest and the most stable teeth in the mesiodistal and buccolingual crown diameters and crown area, while the upper second premolar and the lower first premolar the smallest on the Miyakojima and the Ishigakijima populations. The crown diameters of all posterior teeth in Ishigakijima were smaller than those in Miyakojima. The upper and lower second premolars are proportionately the largest teeth in the crown index. The buccolingual crown diameter and crown area were larger for male than female, showing significant sex difference on the Miyakojima and the Ishigakijima populations. The mesiodistal crown diameters were larger for male than female, showing significant sex difference, premolars and molars except upper molar and lower second premolar on the Miyakojima, and upper first premolar, upper second molar and lower first molar on the Ishigakijima populations. The crown indexes were showing significant sex difference, premolars and molars except upper second premolar and first molar on the Miyakojima, and upper first molars, lower first premolar and second molar on the Ishigakijima populations. Metrical dental characters of the Miyakojima and Ishigakijima populations were compared with these from the others. The Miyakojima population shows close affinities to the Tanegasima and Yayoi populations, and the Ishigakijima similar to the Ainu and Jomon populations. The dental evidence shown in this study may contribute to the establishment of biological relationships between Miyakojima and Ishigakijima populations.