Dental Anthropological Study of Non-metric Traits in the Naxi Nationality of Chinese Minorities

Abstract

The dental anthropological survey of the Naxi tribe, one of the Chinese ethnic minorities, was carried out in Lijiang in Yunnan Province in 2002. The subjects were young adults whose dental impression models were collected, and the frequencies of 22 dental traits were recorded. The results were compared with those of previous studies including Chinese minorities, Dai and Hani, and with other Asian populations in terms of Turner's Mongoloid dental variation theory. A principal coordinate analysis based on Smith's Mean Measure of Divergence using the frequencies of 17 traits suggested that the Naxi tribe positioned close to Dai and Hani and belonged to the Sundadont dentition category, which typifies Southeast Asians, despite its Sinodont (Northeast Asia) location. Other anthropological and linguistic studies also suggest that the Naxi are closely related to Tibetans. With reference to our findings, and to presumed past and present distributions of Sinodonty and Sundadonty, we postulate that the Naxi in Yunnan Province have genetically inherited traits similar to the Sundadont peoples of Southeast Asian, but also exhibit environmentally induced traits similar to those of the Sinodont Han (who comprise the majority of the Chinese population) and other Sinodont tribes in their vicinity. Historical factors both genetic and environmental are, it is argued, reflected in their dental characteristics.