Degenerative changes in human temporomandibular joints in relation to occlusal support.

ABSTRACT

OBJECTIVE: Controversy exists concerning the etiological factors behind degenerative changes in the temporomandibular joints (TMJs). Tooth attrition, occlusal support, food consistency, ageing, gender and genetics are some possible causative factors that have been discussed in the literature. The aim of this study was to examine contemporary human skull material for possible relations between degenerative form and surface changes in the TMJs in relation to occlusal support. MATERIAL AND METHODS: The material consisted of 259 human skulls from 170 males and 89 females, with an age range of 18-100 years. RESULTS: Dental status was in general poor, and 22% of skulls were edentulous. Form and surface changes of both the condyles and the temporal components were more common in the present material compared to that in most previous studies. In males, irrespective of age, only weak and clinically insignificant correlations could be found between degenerative TMJ changes and occlusal support. In women, however, the correlations between these variables were in general much stronger, especially at higher ages. CONCLUSIONS: The present findings do not lend support to the hypothesis that loss of occlusal support is a causative factor for degenerative changes in the TMJs in male subjects. In women, such a correlation was obvious in the present sample, at least at higher ages. It can be speculated that hormonal factors play a role in the sex difference found.