Temporomandibular joint osteoarthritis at Chelechol ra Orrak, Palau

Abstract

ObjectiveTo explore the frequency and severity of temporomandibular joint osteoarthritis (TMJ-OA) and its causative factors in a skeletal assemblage from the prehistoric site of Chelechol ra Orrak, Palau, western Micronesia. Materials50 temporomandibular joint surfaces (mandibular condyles and articular eminences), representing a minimum of 22 adult individuals, 17 of which retain teeth. MethodsJoint surfaces were macroscopically evaluated for characteristics associated with TMJ-OA and joint morphology. Dental remains were scored for tooth wear and staining. ResultsNine individuals (40.1 %) displayed lesions typical of TMJ-OA. The strongest associations were between tooth wear and TMJ-OA. ConclusionsIndirect effects of parafunctional dental activity appear to be a factor in TMJ-OA frequency at Chelechol ra Orrak. While betel nut chewing may be one of those activities, it does not appear to be solely driving the presence of TMJ-OA. SignificanceThis study highlights the association between a specific parafunctional use of the temporomandibular joint and the potential pathological consequences. It also reinforces the need to carefully evaluate the archaeological context of skeletal remains in order to evaluate specific etiological factors in the presence of TMJ-OA in present and past populations. LimitationsSample sizes are limited in this study. This will increase as excavations continue. Suggestions for Further ResearchBecause dental occlusion appears to be associated with TMJ-OA, focus on dental conditions affecting occlusal patterns, such as third molar agenesis, antemortem tooth loss, and malocclusion, and their relationship to TMJ-OA frequency, are recommended.