Electromyographic Changes in the Masseter and Temporalis Muscles Before and After Orthognathic Surgery in Patients With Mandibular Prognathism.

Objective: Evaluate the electromyographic changes in the Masseter (MM) and Temporalis (TM) muscles during voluntary clenching of the teeth both before and after orthognathic surgery in patients aged 18 years and older and diagnosed with mandibular prognathism.

Methods: Eleven patients with prognathism were included in the study, in all of whom the initial phase of orthodontic treatment had been completed. The orthognathic procedure to reduce prognathism comprised intraoral oblique sliding (or subsigmoid) osteotomy, after which intermaxillary fixation with ligaments in the maxilla and mandible was undertaken in all patients for 6 weeks post-surgery.