Morphological and metrical comparison of San and Central Sotho dentitions from southern Africa

Abstract

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.

Brief communication: Early hominin variability in first molar dental trait frequencies

“…The discontinuity (presence/absence) in the visible scale arises from a morphological ''threshold effect'' (Scott and Turner, 1997). For all traits included in this study, standard ASUDAS breakpoints (Turner, 1985(Turner, , 1987 for presence/absence, based on each trait's appraised morphological threshold (Scott, 1973;Haeussler et al, 1989), were used and applied consistently across all data sets. For the five traits examined, these breakpoints are as follows: for UM1 Carabelli's trait, only scores of 5-7, representing the cusp variant, were counted as present; for UM1 cusp 5, scores of 1-5 were counted as present; for the LM1 protostylid, scores of 1-6, including the pit form of the protostylid, were counted as present; for LM1 cusp 6, scores of 1-5 were counted as present; and finally, for LM1 cusp 7, scores of 1-4 represented presence (for a complete description of these traits, see Turner et al, 1991).…”

Characteristic high- and low-frequency dental traits in sub-Saharan African populations

“…The 32 samples (1,635 total dentitions) are a representative cross-section of native African cultural groups and include all of Greenberg's (1959Greenberg's ( , 1966 Haeussler et al, 1989). Thirty-six dental and osseous morphological traits from the maxilla and mandible were observed in those samples with skeletal dentitions (Table 2).…”

The Bushman Maxillary Canine of the Chewa Tribe in East-Central Africa.

“…MORRIS (1975) did not apply the ASU system to his extensive study. However, his data were useful for comparison with those of the Chewa sample because they had been incorporated into a later study which uses the ASU system (HAEUSSLER et al, 1989). Table 3 compares the total frequency of the Bushman Canine for several populations.…”