Patterns of dentitions in East Asia
In
anthropology
,
Sinodonty
and
Sundadonty
are two patterns of features widely found in the
dentitions
of different
East Asians
. These patterns were identified by anthropologist
Christy G. Turner II
as being within the greater "
Mongoloid
dental complex".
[1]
The
combining forms
Sino-
and
Sunda-
refer to
China
and
Sundaland
, respectively, while
-dont
refers to teeth.
Proto-sundadonty hypothesis
[
edit
]
Tsunehiko Hanihara (1993) believed that the dental features of
Aboriginal Australians
have the characteristic of high frequencies of "
evolutionarily conservative characteristics,
" which he called the "
proto-
sundadont" pattern, as he believed that the dental pattern of Aboriginal Australians was ancestral to that of Southeast Asians.
[2]
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, rendering the term "proto-sundadont" inaccurate for the Australian dental morphology. He also shows that sinodonty is predominant in Native Americans.
[3]
Super-Sinodont
[
edit
]
Analysis on the Sinodonty and Sundadonty of New world groups by G.R. Sott et al. (2016) shows the distinction between East 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.
[4]
Mongoloid dental complex
[
edit
]
Turner defined the Sinodont and Sundadont dental complexes in contrast to a broader Mongoloid dental complex.
[5]
Hanihara defined the Mongoloid dental complex in 1966. In 1984, Turner separated the Mongoloid dental complex into the Sinodont and Sundadont dental complexes.
[6]
Ryuta Hamada, Shintaro Kondo and Eizo Wakatsuki (1997) said, on the basis of dental traits, that
Mongoloids
are separated into sinodonts and sundadonts, which is supported by
Christy G. Turner II
(1989).
[7]
[8]
Sundadont
[
edit
]
Turner found the Sundadont pattern in the skeletal remains of
J?mon people
of
Japan
, and in living populations of
Taiwanese indigenous peoples
,
Filipinos
,
Indonesians
,
Borneans
, and
Malays
.
In 1996, Rebecca Haydenblit of the Hominid Evolutionary Biology Research Group at
Cambridge University
did a study on the dentition of four
Pre-Columbian era
Mesoamerican
populations and compared their data to other Eastern Eurasian populations.
[9]
She found that "
Tlatilco
", "
Cuicuilco
", "
Monte Alban
" and "
Cholula
" populations followed an overall Sundadont dental pattern "characteristic of Southeast Asia" rather than a Sinodont dental pattern "characteristic of Northeast Asia".
[9]
Sinodont
[
edit
]
Turner 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".
[10]
- The upper first
premolar
has one root, and the lower first
molar
in Sinodonts has three roots (3RM1).
[10]
[5]
Associated traits
[
edit
]
The
EDAR
gene causes the Sinodont tooth pattern, and also affects hair texture,
[11]
jaw morphology,
[12]
and perhaps the nutritional profile of
breast milk
.
[13]
Applicability
[
edit
]
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
[which?]
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.
[14]
See also
[
edit
]
References
[
edit
]
- ^
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
.
- ^
Pilloud, Marin; Heim, Kelly; Schmitz, Kirk; Paul, Kathleen (2018).
"Sinodonty, Sundadonty, and the Beringian Standstill model: Issues of timing and migrations into the New World"
.
Quaternary International
.
466
: 233.
Bibcode
:
2018QuInt.466..233S
.
doi
:
10.1016/j.quaint.2016.04.027
.
- ^
Pilloud, Marin; Heim, Kelly; Schmitz, Kirk; Paul, Kathleen (2018).
"Sinodonty, Sundadonty, and the Beringian Standstill model: Issues of timing and migrations into the New World"
.
Quaternary International
.
466
: 233.
Bibcode
:
2018QuInt.466..233S
.
doi
:
10.1016/j.quaint.2016.04.027
.
- ^
a
b
Scott, R.G. (1997). Encyclopedia of Human Biology. Second Edition. Volume 3. Pages 175-190. Retrieved December 14, 2016, from
link
.
- ^
Diaz, 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 Medica, 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
.
- ^
a
b
Haydenblit, Rebeca (June 1996). "Dental variation among four prehispanic Mexican populations".
American Journal of Physical Anthropology
.
100
(2): 225?246.
doi
:
10.1002/(SICI)1096-8644(199606)100:2<225::AID-AJPA5>3.0.CO;2-W
.
- ^
a
b
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
.
- ^
Kamberov YG, Wang S, Tan J, Gerbault P, Wark A, Tan L, Yang Y, Li S, Tang K, Chen H, Powell A, Itan Y, Fuller D, Lohmueller J, Mao J, Schachar A, Paymer M, Hostetter E, Byrne E, Burnett M, McMahon AP, Thomas MG, Lieberman DE, Jin L, Tabin CJ, Morgan BA, Sabeti PC (Feb 2013).
"Modeling recent human evolution in mice by expression of a selected EDAR variant"
.
Cell
.
152
(4): 691?702.
doi
:
10.1016/j.cell.2013.01.016
.
PMC
3575602
.
PMID
23415220
.
- ^
Adhikari, K.; Fuentes-Guajardo, M.; Quinto-Sanchez, M.; Mendoza-Revilla, J.; Chacon-Duque, J. C.; Acuna-Alonzo, V.; Gomez-Valdes, J. (2016).
"A genome-wide association scan implicates DCHS2, RUNX2, GLI3, PAX1 and EDAR in human facial variation"
.
Nature Communications
.
7
: 11616.
Bibcode
:
2016NatCo...711616A
.
doi
:
10.1038/ncomms11616
.
PMC
4874031
.
PMID
27193062
.
- ^
Lozovschi, Alexandra (24 April 2018).
"Ancient Teeth Reveal Breastfeeding-Related Gene Helped Early Americans Survive The Ice Age [Study]"
.
Inquisitr
. Retrieved
25 April
2018
.
- ^
Stojanowski, Christopher M.; Johnson, Kent M. (March 2015). "Observer error, dental wear, and the inference of new world sundadonty".
American Journal of Physical Anthropology
.
156
(3): 349?362.
doi
:
10.1002/ajpa.22653
.
ISSN
1096-8644
.
PMID
25363296
.