Sinodonty and Sundadonty
This article needs attention from an expert in anthropology. The specific problem is: it lacks a description of sundadonty.(June 2014)
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". Sundadonty is regarded as having a more generalised, Australoid morphology and having a longer ancestry than its offspring, Sinodonty.
Tsunehiko Hanihara (1993) said that the dental features of Aboriginal Australians have the characteristic of high frequencies of "evolutionarily conservative characteristics," which is called the "proto-sundadont" pattern.
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).
In 1996, Rebecca Haydenblit of the Hominid Evolutionary Biology Research Group at Cambridge University did a study on the dentition of four pre-Columbian Mesoamerican populations and compared their data to "other Mongoloid populations". She 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".
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.
In the 1990s, Turner's dental morphological traits were frequently mentioned as one of three new tools for studying origins and migrations of human populations. The other two were linguistic methods such as 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.[original research?]
Today, 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. Some later studies have questioned this and found Sundadont features in some American peoples.
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- SAO/NASA Astrophysics Data System. Teeth and Prehistory in Asia. Retrieved March 9, 2018, from link to the web page.
- Haydenblit, R. (1996), Dental variation among four prehispanic Mexican populations. American Journal of Physical Anthropology, 100: 225–246. doi: 10.1002/(SICI)1096-8644(199606)100:2<225::AID-AJPA5>3.0.CO;2-W
- 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.