In anthropology, Sinodonty and Sundadonty are two patterns of features widely found in the
dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiolo ...
s of different
populations in East Asia and
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
. These two patterns were identified by anthropologist
Christy G. Turner II
Christy G. Turner II (November 28, 1933, Columbia, Missouri – July 27, 2013, Tempe, Arizona) was an American anthropologist known for his research on dental anthropology, perimortem taphonomy, and his theories about the populating of the Amer ...
as being within the greater "
Mongoloid
Mongoloid () is an obsolete racial grouping of various peoples indigenous to large parts of Asia, the Americas, and some regions in Europe and Oceania. The term is derived from a now-disproven theory of biological race. In the past, other terms ...
dental complex".
The
combining forms ''
Sino-
The names of China include the many contemporary and historical appellations given in various languages for the East Asian country known as ''Zhōngguó'' (/, "middle country") in its national language, Standard Mandarin. China, the name in Engl ...
'' and ''Sunda-'' refer to
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
and
Sundaland
Sundaland (also called Sundaica or the Sundaic region) is a biogeographical region of South-eastern Asia corresponding to a larger landmass that was exposed throughout the last 2.6 million years during periods when sea levels were lower. It ...
, respectively, while refers to teeth.
Proto-sundadonty hypothesis
Tsunehiko Hanihara (1993) believed that the dental features of
Aboriginal Australians
Aboriginal Australians are the various Indigenous peoples of the Australian mainland and many of its islands, such as Tasmania, Fraser Island, Hinchinbrook Island, the Tiwi Islands, and Groote Eylandt, but excluding the Torres Strait Islands ...
have the characteristic of high frequencies of "''evolutionarily conservative characteristics,''" which he called the "
proto-
Proto or PROTO may refer to:
Language
* Proto-, an English prefix meaning "first"
Media
* ''Proto'' (magazine), an American science magazine
*Radio Proto in Cyprus
Music
* ''Proto'' (Holly Herndon album), 2019
* ''Proto'' (Leo O'Kelly a ...
sundadont" pattern, as he believed that the dental pattern of Aboriginal Australians was ancestral to that of Southeast Asians.
[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, fro]
link to the PDF document
C.G Turner II shows with his analysis of 2016 that sundadonty is the proto-East Eurasian dental morphology and is not connected to the Australian dental morphology, debunking the hypothesis that the Australian dental morphology is the "proto-sundadont" dental pattern. He also shows that sinodonty is predominant in Native Americans.
Super-Sinodont
Analysis on the Sinodonty and Sundadonty of New world groups by G.R. Sott et al. (2016) shows the distinction between East Asians and Southeast Asians is not nearly as dramatic as the difference between all Asians and all New World groups. Other researchers like Stojanowski et al., 2013;
Stojanowski and Johnson, (2015) suggest New World groups may be neither Sinodont nor Sundadont and in most regards, could be viewed as super-Sinodont. A clear dental morphology not only ties New World groups to Asians, particularly northeast Asians, but it also exhibits a pattern largely consistent with the Beringian Standstill model (BSM) based on a Sinodont source population.
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, on the basis of dental traits, that
Mongoloid
Mongoloid () is an obsolete racial grouping of various peoples indigenous to large parts of Asia, the Americas, and some regions in Europe and Oceania. The term is derived from a now-disproven theory of biological race. In the past, other terms ...
s are separated into sinodonts and sundadonts, which is supported by
Christy G. Turner II
Christy G. Turner II (November 28, 1933, Columbia, Missouri – July 27, 2013, Tempe, Arizona) was an American anthropologist known for his research on dental anthropology, perimortem taphonomy, and his theories about the populating of the Amer ...
(1989).
[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, fro]
link to the PDF document
Sundadont
Turner found the Sundadont pattern in the skeletal remains of
Jōmon people
is the generic name of several peoples who lived in the Japanese archipelago during the Jōmon period (). The Jōmon people may have consisted of multiple groups, which arrived and merged at different times in the Japanese archipelago, using multi ...
of
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, and in living populations of
Taiwanese aborigines
Taiwanese may refer to:
* Taiwanese language, another name for Taiwanese Hokkien
* Something from or related to Taiwan ( Formosa)
* Taiwanese aborigines, the indigenous people of Taiwan
* Han Taiwanese, the Han people of Taiwan
* Taiwanese people, ...
,
Filipinos
Filipinos ( tl, Mga Pilipino) are the people who are citizens of or native to the Philippines. The majority of Filipinos today come from various Austronesian ethnolinguistic groups, all typically speaking either Filipino, English and/or othe ...
,
Indonesians
Indonesians (Indonesian: ''orang Indonesia'') are citizens or people originally from Indonesia, regardless of their ethnic or religious background. There are more than 1,300 ethnicities in Indonesia, making it a multicultural archipelagic coun ...
,
Borneans
Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and east ...
, and
Malaysians
Malaysians are nationals and citizens who are identified with the country of Malaysia. Although citizens make up the majority of Malaysians, non-citizen residents and overseas Malaysians may also claim a Malaysian identity.
The country is h ...
.
In 1996, Rebecca Haydenblit of the Hominid Evolutionary Biology Research Group at Cambridge University did a study on the dentition of four pre-Columbian
Mesoamerica
Mesoamerica is a historical region and cultural area in southern North America and most of Central America. It extends from approximately central Mexico through Belize, Guatemala, El Salvador, Honduras, Nicaragua, and northern Costa Rica. W ...
n populations and compared their data to other Eastern Eurasian populations.
She found that "
Tlatilco
Tlatilco was a large pre-Columbian village in the Valley of Mexico situated near the modern-day town of the same name in the Mexican Federal District. It was one of the first chiefdom centers to arise in the Valley, flourishing on the western sho ...
", "
Cuicuilco
Cuicuilco is an important archaeological site located on the southern shore of Lake Texcoco in the southeastern Valley of Mexico, in what is today the borough of Tlalpan in Mexico City. Some historians believe this settlement goes back to 1400 B ...
", "
Monte Albán
Monte Albán is a large pre-Columbian archaeological site in the Santa Cruz Xoxocotlán Municipality in the southern Mexican state of Oaxaca (17.043° N, 96.767°W). The site is located on a low mountainous range rising above the plain in the ...
" and "
Cholula" populations followed an overall "Sundadont" dental pattern "characteristic of Southeast Asia" rather than a "Sinodont" dental pattern "characteristic of Northeast Asia".
[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]
Sinodont
Turner found the Sinodont pattern in the
Han Chinese
The Han Chinese () or Han people (), are an East Asian ethnic group native to China. They constitute the world's largest ethnic group, making up about 18% of the global population and consisting of various subgroups speaking distinctive va ...
, in the inhabitants of
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
and eastern
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
, in the
Native Americans, and in the
Yayoi people
The were an ancient ethnicity that migrated to the Japanese archipelago from Korea and China during the Yayoi period (300 BCE–300 CE). Although highly controversial, a single study that utilized radiometric dating techniques inconclusively ...
of Japan.
Sinodonty is a particular pattern of
teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...
characterized by the following features:
* The upper first
incisors
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wh ...
and upper second incisors are
shovel-shaped, and they are "not aligned with the other teeth".
[Kimura, R. et al. (2009). A Common Variation in EDAR Is a Genetic Determinant of Shovel-Shaped Incisors. In ]American Journal of Human Genetics
The ''American Journal of Human Genetics'' is a monthly peer-reviewed scientific journal in the field of human genetics. It was established in 1948 by the American Society of Human Genetics and covers all aspects of heredity in humans, including t ...
, 85(4). Page 528. Retrieved December 24, 2016, fro
link
* The upper first
premolar
The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth ...
has one root, and the lower first
molar in Sinodonts has three roots (3RM1).
[Scott, R.G. (1997). Encyclopedia of Human Biology. Second Edition. Volume 3. Pages 175-190. Retrieved December 14, 2016, fro]
link
Associated traits
The
EDAR
Ectodysplasin A receptor (EDAR) is a protein that in humans is encoded by the EDAR gene. EDAR is a cell surface receptor for ectodysplasin A which plays an important role in the development of ectodermal tissues such as the skin. It is structura ...
gene causes the Sinodont tooth pattern, and also affects hair texture,
jaw morphology, and perhaps the nutritional profile of
breast milk
Breast milk (sometimes spelled as breastmilk) or mother's milk is milk produced by mammary glands located in the breast of a human female. Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates ( lacto ...
.
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
Joseph Harold Greenberg (May 28, 1915 – May 7, 2001) was an American linguist, known mainly for his work concerning linguistic typology and the genetic classification of languages.
Life Early life and education
Joseph Greenberg was born on ...
's
mass comparison
Mass comparison is a method developed by Joseph Greenberg to determine the level of genetic relatedness between languages. It is now usually called multilateral comparison. The method is rejected by most linguists , though not all.
Some of the to ...
of vocabulary or
Johanna Nichols
Johanna Nichols (born 1945, Iowa City, Iowa) is an American linguist and professor emerita in the Department of Slavic Languages and Literatures at the University of California, Berkeley. She earned her Ph.D. in Linguistics at the University of C ...
's statistical study of
language typology
Linguistic typology (or language typology) is a field of linguistics that studies and classifies languages according to their structural features to allow their comparison. Its aim is to describe and explain the structural diversity and the co ...
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
Kennewick Man and Ancient One are the names generally given to the skeletal remains of a prehistoric Paleoamerican man found on a bank of the Columbia River in Kennewick, Washington, on July 28, 1996. It is one of the most complete ancient ske ...
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
hich?/sup> have questioned this and found Sundadont features in some American peoples.
A study done by Stojonowski et al in 2015 found a "significant interobserver error" in the earlier studies and their statistical analysis of matched wear and morphology scores suggests trait downgrading for some traits.
See also
* Ainu people
The Ainu are the indigenous people of the lands surrounding the Sea of Okhotsk, including Hokkaido Island, Northeast Honshu Island, Sakhalin Island, the Kuril Islands, the Kamchatka Peninsula and Khabarovsk Krai, before the arrival of the Y ...
* Australo-Melanesians
Australo-Melanesians (also known as Australasians or the Australomelanesoid, Australoid or Australioid race) is an outdated historical grouping of various people indigenous to Melanesia and Australia. Controversially, groups from Southeast Asia an ...
* Austronesian peoples
The Austronesian peoples, sometimes referred to as Austronesian-speaking peoples, are a large group of peoples in Taiwan, Maritime Southeast Asia, Micronesia, coastal New Guinea, Island Melanesia, Polynesia, and Madagascar that speak Austro ...
* Malay race
The concept of a Malay race was originally proposed by the Germany, German physician Johann Friedrich Blumenbach (1752–1840), and classified as a brown (racial classification), brown race. ''Malay'' is a loose term used in the late 19th century ...
* Odontometrics
Odontometrics is the measurement and study of tooth size. It is used in biological anthropology and bioarchaeology to study human phenotypic variation. The rationale for use is similar to that of the study of dentition, the structure and arran ...
* Shovel-shaped incisors Shovel-shaped incisors (or, more simply, shovel incisors) are incisors whose lingual surfaces are scooped as a consequence of lingual marginal ridges, crown curvature or basal tubercles, either alone or in combination.
Shovel-shaped incisors are ...
References
External links
Affinities of the Paleoindians
{{Historical definitions of race
Teeth
Biological anthropology