Monday 16 November 2009

Race Doesnt Exist - look at the teeth

So race doesnt exist eh !

All you need to do is look at someones teeth and you can tell what race they are !

Tissue contributions to sex and race: Differences in tooth crown size of deciduous molars

Edward F. Harris *, Joseph D. Hicks, Betsy D. Barcroft
College of Dentistry, University of Tennessee, Memphis, Tennessee 38163

This study describes size of constituent deciduous tooth crown components (enamel, dentine, and pulp) to address the manner in which males characteristically have larger teeth than females, and the observation that teeth of American blacks are larger than those of American whites. Measurements were collected (n = 333 individuals) from bitewing radiographs using computer-aided image analysis. Tissue thicknesses (enamel, dentine, pulp) were measured at the crown’s mesial and distal heights of contour. Deciduous mesiodistal molar crown length is composed of about 1/7 enamel, 1/3 dentine, and 1/2 pulp.

Details differ by tooth type, but males typically have significantly larger dentine and pulp dimensions than females; there is no sexual dimorphism in marginal enamel thickness. Males scale isometrically with females for all variables tested here.

Blacks significantly exceed whites in size of all tissues, but tissue types scale isometrically with blacks and whites with one exception: enamel thickness is disproportionately thick in blacks. While the absolute difference is small (5.56 mm of enamel in blacks summed over all four deciduous molar tooth types vs. 5.04 mm in whites), the statistical difference is considerable (P < 0.001). Aside from enamel, crown size in blacks is increased proportionately vis-à-vis whites. Principal components analysis confirmed these univariate relationships and emphasizes the statistical independence of crown component thicknesses, which is in keeping with the sequential growth and separate embryonic origins of the tissues contributing to a tooth crown.

Results direct attention to the rates of enamel and dentine deposition (of which little is known), since the literature suggests that blacks (with larger crowns and thicker enamel) spend less time in tooth formation than whites. Am J Phys Anthropol 115:223-237, 2001. © 2001 Wiley-Liss, Inc.

Put simply, people of African ancestry have bigger teeth with thicker enamel, most notable on the crowns. they are often said to have ‘complex, massive’ teeth, where as Europeans have ’simple, mass reduced’ teeth. It’s an excellent way of telling someone’s ancestry, if you are looking at a skull.

Metric dental variation of major human populations

Tsunehiko Hanihara 1 *, Hajime Ishida 2


Mesiodistal and buccolingual crown diameters of all teeth recorded in 72 major human population groups and seven geographic groups were analyzed. The results obtained are fivefold. First, the largest teeth are found among Australians, followed by Melanesians, Micronesians, sub-Saharan Africans, and Native Americans. Philippine Negritos, Jomon/Ainu, and Western Eurasians have small teeth, while East/Southeast Asians and Polynesians are intermediate in overall tooth size. Second, in terms of odontometric shape factors, world extremes are Europeans, aboriginal New World populations, and to a lesser extent, Australians.

Third, East/Southeast Asians share similar dental features with sub-Saharan Africans, and fall in the center of the phenetic space occupied by a wide array of samples.

Fourth, the patterning of dental variation among major geographic populations is more or less consistent with those obtained from genetic and craniometric data. Fifth, once differences in population size between sub-Saharan Africa, Europe, South/West Asia, Australia, and Far East, and genetic drift are taken into consideration, the pattern of sub-Saharan African distinctiveness becomes more or less comparable to that based on genetic and craniometric data. As such, worldwide patterning of odontometric variation provides an additional avenue in the ongoing investigation of the origin(s) of anatomically modern humans. Am J Phys Anthropol, 2005. © 2005 Wiley-Liss, Inc.

Add to Technorati Favorites

No comments: