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Trait analysis of the dentition of the Tarahumara Indians and Mestizos of the Sierra Madre Occidental, Mexico
Author(s) -
Snyder Richard G.,
Dahlberg Albert A.,
Snow Clyde C.,
Dahlberg Thelma
Publication year - 1969
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/ajpa.1330310109
Subject(s) - trait , penetrance , sexual dimorphism , expressivity , concordance , cusp (singularity) , dentition , demography , mongoloid , biology , geography , zoology , sociology , population , genetics , phenotype , paleontology , geometry , mathematics , computer science , programming language , gene
A new approach of trait analysis of the dentition is presented, based upon study of both deciduous and permanent dentitions of 114 Tarahumara Indians and 63 Mestizos of both sexes and ranging in age from 5 to 23 years. Molar cusp patterns and numbers, and odontometries were analyzed and compared, and penetrance, sexual dimorphism, and concordance were investigated. To examine penetrance and expressivity of Carabelli's cusp and the protostylid, five categories of description of the surface upon which these cusps normally appear were made. Of particular importance was the finding that when expressivity of these traits is examined based upon a trait analysis scale which includes the entire range of expressions of the trait the frequency may be much higher than generally believed. Carabelli's cusp ranged from 95% for Mestizo males to 100% for Tarahumara males, although low frequency has been previously considered a Mongoloid trait. Current work is underway to re‐examine several previous American Indian dental collections utilizing this technique of more discrete trait analysis.