UCSF

The temporomandibular joint (TMJ) is a complex structure that joins the temporal bone to the mandible in order to facilitate mastication and speech. All the components of the TMJ must work in tandem with the contralateral side to produce the dynamic movements required for speech and mastication. Any dysfunction between the two TMJs or within one TMJ itself may lead to painful or non-painful temporomandibular disorders (TMDs). There is a wide range of causes for TMDs, including biomechanical, biological, and bio-psychosocial factors, but there are limited treatment options available due to a lack of understanding of the etiology and pathogenesis of TMDs. In order to provide improved interventions and treatment, there needs to be a better understanding of the etiopathogenesis of TMDs at the tissue, cellular, and molecular level. One specific area of interest is the mandibular condylar cartilage (MCC), which has been shown to undergo cellular changes in response to altered occlusion in mice. The aim of this study was to examine how the TMJ responds to altered occlusion (unilateral maxillary molar tooth extractions) in skeletally and dentally mature mice to better understand the adaptive potential of the TMJ and progression of occlusal-related TMDs. The results showed that there were no changes in morphology of the condyle or cellular organization of the MCC in adult mice after extraction of the 3 maxillary right molars, and thus, no adaptive changes occur in response to altered occlusion in skeletally mature mice with stable occlusion.