Longitudinal Study Involving Obesity in Women and Bariatric Surgery: An Electromyographic Approach to the Masseter and Temporal Muscles.

This longitudinal study was aimed to evaluate the electromyographic activity (EMG) of the masticatory muscles during mandibular tasks in women with grade II and III obesity, who were eligible for bariatric surgery. Twenty-one patients were followed up for 3 and 6 months after the Roux-en-Y gastric bypass. The EMG included analyses of the masseter and temporalis muscles during rest, right and left laterality, protrusion, and dental clenching at maximal voluntary contraction with and without parafilm. Data were tabulated and submitted for statistical analysis using the repeated measures test (P<0.05) with the Bonferroni post-test. Significant differences were observed between the right temporal muscle during maximal voluntary contraction (P=0.003) and maximal voluntary contraction with Parafilm M for the right masseter (P=0.01), left masseter (P=0.03), right temporal (P=0.002), and left temporal (P=0.03) muscles. There was gradual decrease in the resting EMG of the masticatory muscles 6 months after surgery. There was an increase in the EMG of the muscles that are the most active in the neuroanatomical movements of laterality and protrusion 6 months after surgery. There was an increase in EMG in maximal voluntary contraction with and without parafilm, 3 and 6 months after surgery. This study suggests that women with severe obesity who underwent bariatric surgery had better functional results of the masticatory muscles 3 and 6 months after the procedure, which is an important parameter in surgical planning, functional recovery, and nutritional status.