Tooth wear and dentoalveolar remodeling are key factors of morphological variation in the Dmanisi mandibles

The mandibles of the early Pleistocene hominins from Dmanisi, Georgia, exhibit wide morphological variation, but the causes of diversity remain largely unknown. Here we quantify the effects of heavy tooth wear and wear-related bone remodeling on mandibular variation. Using modern hunter-gatherer populations as a reference, we show that features such as dental arcade form, mandibular corpus height, and symphyseal inclination change substantially with progressive tooth wear. These data indicate that the Dmanisi mandibles reflect normal within-population variation augmented by interindividual differences in wear-related bone remodeling. Dmanisi further provides the first clear evidence for toothpick-induced local periodontitis. This study illustrates how excessive tooth wear leads to dentognathic pathology and complete tooth loss, which was evidently compensated for by culturally mediated food processing.