Sinodonty and Sundadonty

Anthropologist Christy Turner identified two patterns, Sinodonty and Sundadonty, for East Asia, within the "Mongoloid dental complex"^[1]. The latter is regarded as having a more generalised, Australoid morphology and having a longer ancestry than its offspring, Sinodonty.

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Sino and Sunda refer to China and Sundaland, while 'dont' refers to teeth.

He found the Sundadont pattern in the Jōmon of Japan, Taiwanese aborigines, Filipinos, Indonesians, Thais, Borneans, Laotians, and Malaysians, and the Sinodont pattern in the inhabitants of China, Mongolia, eastern Siberia, Native Americans, and the Yayoi.

Sinodonty is a particular pattern of teeth common among Native Americans and some peoples in Asia, in particular the northern Han Chinese and some Japanese populations. The upper first two incisors are not aligned with the other teeth, but rotated a few degrees inward, and, moreover, they are shovel-shaped; the upper first premolar has one root (whereas the upper first premolar in Caucasians has normally two roots). The lower first molar in Sinodonts has three roots (whereas it has two roots in Caucasians).

In the 1990s, Turner's dental measurements were frequently mentioned as one of three new tools for studying origins and migrations of human populations. The other two were linguistic methods like Joseph Greenberg's mass comparison of vocabulary or Johanna Nichols's statistical study of language typology and its evolution, and genetic studies pioneered by Cavalli-Sforza.

Today, the largest number of references on the web to Turner's work are from discussions of the origin of Paleo-Indians and modern Native Americans, including the Kennewick Man controversy. Turner found that the dental remains of both ancient and modern Indians are more similar to each other than they are to dental complexes from other continents, but that the Sinodont patterns of the Paleoindians identify their ancestral homeland as north-east Asia. Some later studies have questioned this and found Sundadont features in some American peoples.

Notes

References

• The Anthropology of Modern Human Teeth: Dental Morphology and Its Variation in Recent Human Populations by George Richard Scott, Christy G Turner II.; Cambridge University Press 1997; ISBN 0521784530 - Google Book Search
• The Journey of Man by Spencer Wells; Princeton University Press 2002; ISBN 0-691-11532-X