Sinodonty and Sundadonty
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".[2] Sundadonty is regarded as having a more generalised, Australoid morphology and having a longer ancestry than its offspring, Sinodonty.
The combining forms Sino- and Sunda- refer to China and Sundaland, respectively, while -dont refers to teeth.
Mongoloid Dental Complex
"In contrast to the broad Mongoloid Dental Complex," Turner defined the Sinodont and Sundadont dental complexes.[3] Hanihara defined the Mongoloid Dental Complex in 1966. In 1984, Turner separated the Mongoloid Dental Complex into the Sinodont and Sundadont dental complexes.[4]
Description
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.
By contrast, he found 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".[5]
- 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.[5][3]
Applicability
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.
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.
For example, 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".[6] 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".[6]
Data tables
| Population | Period | Provenance | N | Author | |
|---|---|---|---|---|---|
| Sundadont | Negrito | Modern | Aeta, Philippine | 21 | Hanihara (1990) |
| Filipino | Modern | Philippine (Unspecified ethnicity) | 20 | Cruz (1971) | |
| Filipino | Modern | Manila, Philippine (Tagalog) | 100 | Potter et al. (1981) | |
| Filipino | Modern | Manila, Philippine (Tagalog) | 110 | Hamada, Kondo & Wakatsuki (1997) | |
| Thai | Modern | Bangkok, Thailand | 110 | Matsumura (1994) | |
| Indonesians | Modern | Java, Celebes, Sumatra, Kalimantan Islands | 47 | Matsumura (1995) | |
| Okinawans | Modern | Okinawa, Japan | 25 | Hanihara (1989) | |
| Hokkaido Ainu | Modern | Hokkaido, Japan | 61 | Matsumura (1994) | |
| Jomon | Neolithic | Whole Japan | 711 | Matsumura (1994) | |
| Tanegashima Yayoi | Aeneolithic | Tanegashima Island, Japan | 60 | Matsumura (1994) | |
| Sinodont | Northern Kyushu Yayoi | Aeneolithic | Fukuoka and Yamaguchi prefs., Japan | 212 | Matsumura (1994) |
| Kofun | Prothohistoric | Kanto, Kinki, Northern Kyushu, Japan | 287 | Matsumura (1994) | |
| Kamakura | Early Medieval | Kanto, Japan | 364 | Matsumura (1994) | |
| Edo | Early Modern | Kanto, Japan | 254 | Matsumura (1994) | |
| Modern Japanese | Modern | Kanto, Japan (Showa Univ.) | 105 | Hamada, Kondo & Wakatsuki (1997) | |
| Koreans | Modern | Seoul, Korea | 120 | Cho (1973) | |
| Ugra Mongolians | Early Modern | Ulan Bator, Mongol | 132 | Matsumura (1995) | |
| Taiwan Chinese | Modern | Kaohsiung, Taiwan | 103 | Liao (1984) | |
| Northern Chinese | Modern | Northern China | 149 | Matsumura (1994) | |
| Beijing Chinese | Modern | Beijing, China | 25 | Miura et al. (1991) | |
| Paiwan | Modern | Taiwan | 95 | Sasaki (1982) | |
| Rukai | Modern | Taiwan | 79 | Nagayama (1984) | |
| Bunun | Modern | Taiwan | 89 | Kudo (1985) | |
| Atayal | Modern | Taiwan | 182 | Takei (1990) | |
| Population | Shovel-Shape | Protostylid | Defl. Wrinkle | 6th Cusp | 7th Cusp | |
|---|---|---|---|---|---|---|
| di1 | di2 | dm2 | dm2 | dm2 | dm2 | |
| Japanese | 76.6 (124) | 93.3 (163) | 44.7 (152) | 71.6 (201) | 36.9 (92) | 73.7 (156) |
| Pima Indian | 61.6 (78) | 64.3 (98) | 89.0 (118) | 84.3 (115) | 36.8 (117) | 72.9 (118) |
| Eskimo | 50.0 (16) | 60.0 (5) | 67.3 (52) | 67.9 (53) | 37.7 (53) | 79.4 (63) |
| Am. White | 0.0 (20) | 0.0 (24) | 14.5 (55) | 13.0 (54) | 7.3 (55) | 40.7 (54) |
| Am. Negro | 10.0 (10) | 15.0 (22) | 17.0 (47) | 19.1 (47) | 14.0 (50) | 46.8 (47) |
| Ainu | 50.0 (4) | 66.7 (9) | 45.5 (22) | 70.0 (20) | 23.8 (21) | 71.4 (21) |
| Figures in parenthesis show numbers of individuals observed. | ||||||
| Variant | Sundadont Mean % frequency (range) | Sinodont Mean % frequency (range) | |
|---|---|---|---|
| Upper 1st incisor shoveling (grades 3–6) | 31 (0–65) | 71 (53–92) | |
| Upper 1st incisor double-shoveling (grades 2–6) | 23 (0-60) | 56 (24–100) | |
| One-rooted upper 1st pre-molars | 71 (50–90) | 79 (61–97) | |
| Upper 1st molar enamel extension (grades 2–3) | 26 (0–50) | 50 (18–62) | |
| Peg/reduced/absent upper 3rd molars | 16 (0–27/51) | 32 (16–46) | |
| Deflecting wrinkle in lower 1st molars (grades 2–3) | 26 (0–58) | 44 (0–86) | |
| Three-rooted lower 1st molars | 9 (0–19) | 25 (14–41) | |
| Four-cusped lower 2nd molars | 31 (6–64) | 16 (4–27) | |
See also
References
- ↑ 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
- 1 2 Scott, R.G. (1997). Encyclopedia of Human Biology. Second Edition. Volume 3. Pages 175-190. Retrieved December 14, 2016, from link.
- ↑ 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.
- 1 2 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.
- 1 2 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
- ↑ Hamada, R., Kondo, S. & Wakatsuki, E. (1997). Odontometrical Analysis of Filipino Dentition. In The Journal of Showa University Dental Society, 17. Page 198. Retrieved December 27, 2016, from link.
- ↑ Hanihara, K. (1970). Mongoloid Dental Complex in the Deciduous Dentition with Special Reference to the Dentition of the Ainu. In Journal of the Anthropological Society of Nippon, 78(1). Page 6. Retrieved December 26, 2016, from link.
- ↑ Hillson, S. (2002). Dental Anthropology. United Kingdom: Cambridge University Press. Retrieved December 14, 2016 from link.