Sinodonty and Sundadonty
In anthropology, Sinodonty and Sundadonty are two patterns of features widely found in the dentitions of different populations in East Asia. These two patterns were identified by anthropologist Christy G. Turner II as being within the greater "Mongoloid dental complex". The names are from the names of China (Sino-) and of the Sunda Shelf (ultimately from the ethnonym Sunda), respectively, compounded with -dont for "teeth".
Sundadonty is the ancestral, proto-Mongoloid type, Sinodonty the derived one. Sundadonty is thus closer to Australoid morphology, the dental features of Aboriginal Australians being described as "proto-sundadont" by Hanihara (1993:26).
Mongoloid dental complex
Turner defined the Sinodont and Sundadont dental complexes in contrast to a broader Mongoloid dental complex. Hanihara defined the Mongoloid dental complex in 1966. In 1984, Turner separated the Mongoloid dental complex into the Sinodont and Sundadont dental complexes.
Ryuta Hamada, Shintaro Kondo and Eizo Wakatsuki (1997) said that, based on dental traits, Mongoloids are separated into sinodonts and sundadonts, which is supported by Christy G. Turner II (1989).
Turner found the Sundadont pattern in the skeletal remains of Jōmon people of Japan, and in living populations of Taiwanese aborigines, Filipinos, Indonesians, Borneans, and Malaysians, and the Sinodont pattern in the Han Chinese, in the inhabitants of Mongolia and eastern Siberia, in the Native Americans, and in the Yayoi people of Japan.
Sinodonty is a particular pattern of teeth characterized by the following features:
- The upper first incisors and upper second incisors are shovel-shaped, and they are "not aligned with the other teeth".
- The upper first premolar has one root (whereas the upper first premolar in Caucasians normally has two roots), and the lower first molar in Sinodonts has three roots (3RM1) whereas it has two roots in Caucasoid teeth.
Amerind dental morphology
Today,[year needed] the largest number of references to Turner's work are from discussions of the origin of Paleo-Amerindians and modern Native Americans, including the Kennewick Man controversy. Turner found that the dental remains of both ancient and modern Amerindians are more similar to each other than they are to dental complexes from other continents, but that the Sinodont patterns of the Paleo-Amerindians identify their ancestral homeland as north-east Asia.
Haydenblit (1996) in a study on the dentition of four pre-Columbian Mesoamerican populations found that Tlatilco, Cuicuilco, Monte Albán and Cholula populations followed an overall "Sundadont" dental pattern "characteristic of Southeast Asia" rather than a "Sinodont" dental pattern "characteristic of Northeast Asia".
- Howells, William W. (1997). Getting Here: the story of human evolution. ISBN 0-929590-16-3
- G. Richard Scott, Christy G. Turner, (2000). The Anthropology of Modern Human Teeth: Dental Morphology and Its Variation in Recent Human Populations. Cambridge University Press. ISBN 0521784530
- Hanihara, Tsunehiko. (1993). Craniofacial Features of Southeast Asians and Jomonese: A Reconsideration of Their Microevolution Since the Late Pleistocene. Anthropological Science, 101(1). Page 26. Retrieved March 8, 2018, from link to the PDF document.
- Scott, R.G. (1997). "Encyclopedia of Human Biology" (PDF) (2nd ed.). pp. 175–190. Archived from the original (PDF) on 22 December 2014. Retrieved 14 December 2016.
- Díaz, E. et al. (2014). Frequency and variability of dental morphology in deciduous and permanent dentition of a Nasa indigenous group in the municipality of Morales, Cauca, Colombia. In Colombia Médica, 45(1). Pages 15–24. Retrieved December 14, 2016, from link.
- Hamada, Ryuta, Kondo, Shintaro & Wakatsuki, Eizo. (1997). Odontometrical Analysis of Filipino Dentition. The Journal of Showa University Dental Society, 17. Page 197. Retrieved March 8, 2018, from link to the PDF document.
- SAO/NASA Astrophysics Data System. Teeth and Prehistory in Asia. Retrieved March 9, 2018, from link to the web page.
- Kimura, R. et al. (2009). A Common Variation in EDAR Is a Genetic Determinant of Shovel-Shaped Incisors. In American Journal of Human Genetics, 85(4). Page 528. Retrieved December 24, 2016, from link.
- Haydenblit, R. (1996), Dental variation among four prehispanic Mexican populations. American Journal of Physical Anthropology, 100: 225–246.
- Christy G. Turner II, Sundadonty and Sinodonty in Japan: The Dental Basis for a Dual Origin Hypothesis for the Peopling of the Japanese Islands (1992) (nichibun.ac.jp)
- Christy G. Turner II, "Major features of Sundadonty and Sinodonty, including suggestions about East Asian microevolution, population history, and late Pleistocene relationships with Australian Aboriginals", Am J Phys Anthrop 82.3 (July 1990), 295–317, doi:10.1002/ajpa.1330820308.