Study on the Effects and Mechanisms of Occlusal Adjustment to TMD Pain

Objective: To investigate the effect and possible mechanisms of occlusal adjustment to patients of temporomandibular disorders(TMD) with oral-facial pain.Methods: Fifty-eight patients were divided into two groups,those without any of following three types of occlusions,were assigned to group A(35 cases) and the others were assigned to group B(23 cases).They were impinging occlusion,occlusion that with posterior cusp-to-cusp contact relationship,or the occlusion with 3 or more in-continuous pairs of cross-bite posterior teeth.Visual Analog Scale(VAS) value,EMG activities of bilateral anterior temporolis(TA) and masseter muscle(MM),and occlusal contact points(with Dental PresaleTM Occluzer) during biting in intercuspal position were recorded prior to and immediately after occlusal adjustment,then recorded one month later.Results: 1)In group A,the VAS values decreased remarkably(P0.01)both immediately after occlusal ajustment and one month later,while in group B the decrease of VAS value could only be detected after 1 month of occlusal adjustment(P0.05).2) In group A,the symmetry of bilateral activity of TA and MM was improved significantly after 1 month of occlusal adjustment(P0.05),but in group B,no similar results were found(P0.05).3) In group A,the occlusal contact number increased and more symmetrically distributed after 1 month of occlusal adjustment(P0.05) but these features were not found in Group B(P0.05).4) The treatment effect was not influenced by the degree of TMJ pathological features on radiographs,disease period and age.Conclusion: Occlusal adjustment could effectively release TMD pain that raised without special cause,although the effect depended on the occlusion type.