Electromyography of masseter muscles during habitual mastication in individuals with and without malocclusion

Katia Alonso RODRIGUES, Léslie Piccolotto FERREIRA

The purpose of this study was to verify if malocclusion interferes with the electromyographic activity of masseter muscles during habitual mastication. For such purpose, 37 individuals participated in the research, and three different groups were formed according to occlusion classiication: 9 individuals with clinically normal occlusion (G1); 17 individuals with Angle Class I malocclusion (G2); 11 individuals with Angle Class II division 1 malocclusion (G3). All individuals were female, ranging from 20 years 7 months old to 30 years 8 months old, with natural permanent teeth. The individuals were selected by applying a speciic protocol that was supplemented by an oral myofunctional clinical exam. Bilateral masseter muscle’s activity in the supericial portion was then investigated by electromyographic evaluation using surface electrodes. Fifteen mastication sequence cycles at regular speed were recorded. Results showed that such difference was signiicant, with reduced electromyographic activity between G1, G2 and G3, respectively. Also, when compared on a two-by-two basis, such groups behaved differently: G1 did not present any signiicant differences in electromyographic activity, when compared to G2; G3 showed lower electromyographic activity in relation to G1; no signiicant differences were found in electromyographic activity between G2 and G3, but G2 presented a trend to increased electromyographic activity, as compared to G3. The author concluded that malocclusion contributed to the existence of different electromyographic activity during habitual mastication.

Keywords: Malocclusion. Electromyography. Masseter muscle. Muscle contraction. Mastication.

Tuesday, April 30, 2024 20:49