Longitudinal effects of rapid maxillary expansion on masticatory muscles activity

Background To investigate the modifications induced by rapid maxillary expansion (RME) on the electromyographic (EMG) activities of the anterior temporal and superficial masseter muscles, in patients without pre-treatment EMG alterations. Material and methods Twenty-one patients with unilateral posterior cross-bite selected from the orthodontic department of the University of L'Aquila (Italy), were enrolled. There was no control group in this study since each subject acted as a control of her/himself. Two surface EMG recordings were taken: T0 (before RME) and at T1 (3 month after the end of expansion). To verify the neuromuscular equilibrium, the EMG activities of both right and left masset…