Angular and linear measurements of maxillary first molar occlusal polygons are given for young San (Bushmen), Sotho, Asiatic Indians, Whites, and Papago Indians. Angular and linear measurements are inseparably related. Much greater variation occurs in widths than in lengths. Maximum variation occurs between San and Papago. Papago maxillary first molars are separable from Old World molar samples in two of four angles and eight of 13 indices.
Comparative morphological and metrical study of San and Central Sotho dentitions indicates that the teeth of the two samples are significantly different from one another. The San dental complex contains traits that add mass to the occlusal surface of microdontic dentitions: moderate low-grade UI1 (13.5%) and UI2 shoveling (24.7%), high Bushman canine (43.1%), fairly low UM2 hypocone reduction (23.3%), high UM2 cusp 5 (55.6%), high LM1 cusp 7 (35.2%), LM1 distal trigonid crest (7.1%), and LM2 deflecting wrinkle (5.3%), lack of reduction of LM1 and LM2 cusp number, in the presence of very low UM1 Carabelli's trait (6.7%) and high LM2 Y-groove (86.3%). Culturally, males occasionally exhibit filed UI1 and females are missing LI1. Conversely, mesodontic Central Sotho dentitions display a more simplified morphology, with the exception of moderately high incidence of UM1 Carabelli's trait (41.0%) and very high LM1 cusp 7 (71.3%). Discriminant analysis of mesiodistal and buccolingual diameters and tooth crown surface area data for the left maxillary teeth supports classification of San dentitions as microdont and Central Sotho dentitions as mesodont. Additionally, metrical analysis indicates that San teeth are more sexually dimorphic than are those of Central Sotho.
The utility of the traditional Dryopithecus pattern observations on mandibular molars in hominid dental analysis has been challenged recently from several points of view. Both fossil and contemporary evidence suggest the independence of cusp number and groove pattern on mandibular molars and the quality of dentitions which are normally available for study make it difficult to determine both aspects of pattern (cusp number, groove pattern) equally. Now this paper shows that one of the polymorphisms on the occlusal surface of mandibular molars, the “deflecting wrinkle,” may be responsible for the spurious appearance of a Y molar pattern. It presence serves to insure a “2–3 contact” and hence the identification of the Y molar pattern. While seldom reported in traditional dental data, the wrinkle varies in frequency from 7% in South African white first permanent molars to 78.5% in Bushmen. Elsewhere, Hanihara has proposed that it be considered part of the “Mongoloid dental complex”.
A quantitative technique for obtaining angular data on human maxillary first premolar teeth is presented. Measurement indicates that North American Indian buccal cusps are either buccolingually compressed mesially, or expanded distally, or both, when compared with non-Indian teeth. Surprisingly, data on Chinese and Eskimo samples are similar to non-Indian teeth rather than Indian teeth. Similar techniques may be applied to the more complex multicusped molar teeth in order to extract quantitative data from them.
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