Evaluation of the effect of unilateral mastication on the morphology of temporomandibular joint from the perspective of dynamic joint space

Background: Unbalanced alterations of temporomandibular joint morphology were associated with unilaterally masticatory habits.Objective: This study aimed to investigate the effect of unilateral mastication on the remodelling of the temporomandibular joint using dynamic joint space.Methods: Twelve volunteers with non-maxillofacial deformity and healthy temporomandibular joints were recruited. The 3D models of the mandible and the maxilla were reconstructed according to computed tomography. The subjects were asked to masticate French fries and peanuts unilaterally, which was recorded by a 3D motion capture system. The dynamic joint space during unilateral mastication was analysed.Results: During early closure, the joint space reduction on the non-masticatory side was significantly greater than on the masticatory side (p < .05). During later closure, the joint space reduction on the non-masticatory side was significantly lower than that on the masticatory side (p < .05). The difference in joint space reduction between both sides was greater than the French fries while masticating the peanuts.Conclusions: Unilateral mastication resulted in a different major pressure area on the bilateral TMJs. Therefore, unilateral mastication might be an essential factor in the bilateral asymmetrical remodelling of the TMJ.