Date of Award


Document Type


Degree Name

Master of Dental Science (MDS)



Research Advisor

Robert Brandt D.D.S, M.S.


David Cagna, D.M.D., M.S Mark Scarbecz, Ph.D. Russell Wicks, D.D.S., M.S.


Complete denture, EMG, Muscle activity, Occlusion, T Scan


In the last three decades, little scientific progress has been seen in relation to the occlusal aspects in complete dentures. Equal distribution of loading forces to the edentulous denture foundation is an important factor affecting stability, patient comfort and acceptance of complete dentures. Also, understanding the functional behavior of masticatory muscles for complete denture wearers is important for diagnosing and planning the clinical treatment.

The purpose of the present study was to determine the effect of unilateral and bilateral occlusal interferences on the masticatory muscle activity in edentulous patients, and how patients respond to occlusal interferences both physiologically and psychologically over a brief period of time.

In ten subjects rigid bilateral intercuspal interferences were placed on the most distal teeth of the mandibular complete denture. Subjects were asked to clench maximally and the surface EMG of the right and the left masseter and the temporalis muscles were recorded. Bilateral interferences were removed and the subjects were divided into two groups. Group A received unilateral right interference and group B received unilateral left interference. Surface EMG of the right and the left masseter and the temporalis muscles was recorded at maximal clench. Occlusal interference was removed for both the groups and final EMG recordings were made at maximal clench for all patients. Patients responded to questionnaires after each intervention and finally after removal of occlusalinterference.

Student’s paired T test was used to analyze the data. Results demonstrated no significant difference in EMG values of the patients at baseline and after the introduction of bilateral interferences. There was no significant difference in the EMG values of patients at baseline and after the introduction of unilateral right interferences. In the 5 patients with unilateral left occlusal interferences there was a significant reduction in the EMG activity of the left masseter. There was also no significant difference in the EMG values at baseline and after the removal of occlusal interferences. The analysis of the questionnaires did not reveal any significant finding.