Masseter muscles electromyography study of individuals with and without malocclusion during dental clenching.

The present study had as an objective to verify the electromyographic activity of the masseter muscles during intercuspal maximal clenching in individuals with and without malocclusion. For such purpose, 37 individuals participated, constituting three distinct groups according to the classification of the occlusion: 9 individuals with clinically normal occlusion (G1), 17 individuals with Angle Class I malocclusion (G2) and 11 individuals with Angle Class II division 1 malocclusion (G3). All participants were female, between the ages of 20 years, 7 months to 30 years, 8 months, with permanent natural teeth. The selection of the individuals was made with the application of a specific protocol, being complemented with an oral clinical myofunctional exam. The activity of the bilateral muscle masseter was investigated, in its superficial portion, by means of electromyographic evaluation with surface electrodes. Three consecutive intercuspal maximal clenching were recorded. The results showed that there was not significant statistical difference from the eletromyographic activity between the three groups. The conclusion was that the malocclusion did not interfere in the eletromyographic activity of the masseter muscles.