Three-Dimensional Proxies to Dental Wear Characterization in a Known Age-at-Death Skeletal Collection

Abstract

Dental wear is a function of age-at-death in human skeletal populations. However, discrete scoring proxies of dentine exposure areas have shown to largely depend on dietary life-history and cultural practices. In addition, dental wear greatly limits research on dental morphological variability since unworn teeth are scarce in osteo-archaeological repositories. Age at death is seldom known, and actual trends in dental crown loss are generally assumed to be age-dependent. We applied three-dimensional (3D) dental crown continuous metrics (geometric morphometrics and topographic shape descriptors) to explore the association of first and second permanent maxillary (UM1 and UM2) and mandibular (LM1 and LM2) molar wear with age in the Coimbra International Exchange known age-at-death skull collection. Results are indicative of significant regressions between the morphometric variables and age-at-death, though showing coefficients of determination of 1.4–23.9%. The precision percentages for determining age-at-death from dental crown shape varied from 31.8 to 45.3%, while a significant portion of the overall shape variation of the molar teeth studied could be attributed to anatomical traits independently of dental wear, since modern human populations display a great variability in cusp patterns and molar teeth relative size.