Temporomandibular joint osteoarthritis in human ancient skeletal remains from Late Holocene in southern Patagonia

Abstract

Low prevalence of caries, high stages of dental attrition (DA), and moderate frequency of antemortem tooth loss (AMTL) were found in skeletal remains of hunter-gatherers from southern Patagonia. However, osteoarthritis (OA) of temporomandibular joint (TMJ), possible related to oral health, has not been studied so far. The influence of hunter-gatherer living conditions on the development of TMJ-OA was scarcely evaluated, and analyses of degenerative changes of TMJ in nonindustrialized groups are needed. The aim of this study is to analyse the association between degenerative changes of TMJ, oral disease, and palaeodietary patterns in skeletal remains of hunter-gatherers from southern Patagonia. Degenerative changes of TMJ were recorded in 25 adult skulls of both sexes. Eburnation of articular eminence and/or mandibular condyle was considered as pathognomonic of OA. In the absence of eburnation, OA was diagnosed when two or more of the following lesions were identified: (a) new bone formation on joint surface, (b) new bone formation of joint margins, (c) porosity on the joint surface, and (d) modification of joint contour. In the studied skeletons, it was found that OA prevalence is 28%, similar to those observed in other hunter-gatherer populations elsewhere. TMJ-OA is mostly related to AMTL and older age, but no relation was found with caries and DA, sex, region, dietary patterns, and chronology. However, consumption of terrestrial resources in the diet cannot be discarded as a related factor. Further studies are necessary to explore the morphological variability of the mandible and its possible relationship with different diets and dental pathologies in these populations.