PURPOSE: To analyze the difference between both sides of the face during the electromyographic activity of the masseter muscle in adults with normal occlusion. METHODS: Thirty healthy individuals with ages ranging from 21 to 30 years old were selected. Surface electromyography was performed on right and left masseter muscles during maximal voluntary clenching and habitual chewing with raisins. The mean values of three teeth clenching and fifteen seconds of habitual chewing were calculated for each subject. The analysis considered the sides with higher and lower electromyographic activity. RESULTS: During maximal voluntary clenching, the mean difference between sides was 20.0 microvolts (μV), with confidence interval (95%) between 14.0 and 26.0 μV. During habitual chewing, the mean difference between sides was 10.3 μV, with confidence interval (95%) between 6.7 and 13.8 μV. CONCLUSION: There was a statistically significant difference between both sides of the face in healthy adult subjects, with a relation between sides of 24% for maximal voluntary clenching and 27% during habitual chewing.
Mastication; Electromyography; Masseter muscle; Dental occlusion
