Immediate Effect of Occlusal Errors on Masticatory Muscle Activity in Denture Wearers: A Pilot Study

Over the past three decades, little scientific progress has been made relative to occlusion in conventional complete dentures. Equal distribution of functional load throughout the residual denture foundation is likely an important factor in prosthesis stability and patient acceptance of dentures. A better understanding the relationship between denture occlusion and the physiologic behavior of muscles involved in mastication may prove beneficial in the clinical management of edentulism. The purpose of the present study was to determine the short-term immediate effects of unilateral and bilateral posterior occlusal interferences on masticatory muscle activity in edentulous patients treated with conventional complete dentures. Bilateral EMG activity of the anterior temporalis and masseter muscles was recorded in ten subjects at baseline, following introduction of unilateral posterior occlusal interferences, and following introduction of bilateral posterior interferences. During each experimental event, muscle activity was recorded bilaterally at maximal clench and the intended denture occlusion was electronically verified. Patients responded to questionnaires after each experimental intervention and following removal of occlusal interferences. Student’s paired t-test was used to compare the data obtained (p = 0.05). Results indicate no significant difference in EMG values at baseline, after introduction of bilateral posterior interferences, after the introduction of unilateral right posterior interferences and after removal of the occlusal interference. In the group with unilateral left posterior occlusal interferences there was a significant reduction in the EMG activity of the left masseter. Analysis of questionnaires did not reveal any significant findings. Taken together, results suggest that there was no significant difference in the EMG values of the patient after the introduction of the posterior interferences.