Unilateral posterior crossbite in adolescents: Surface electromyographic evaluation

Aim Unilateral posterior crossbite (UPCB) is characterised by an inverse relationship of the upper and lower buccal dental cusps and may involve one or several teeth. The aim of this study was to compare the electromyographic outcomes of patients with UPCB and those of healthy controls. Materials and methods Fifteen patients (mean age 11.5 years) with UPCB and fifteen healthy controls (mean age 12 years) were examined at the Department of Orthodontics, Second University of Naples. Surface electromyography was performed on patients and controls. Results and conclusion Patients with UPCB had less muscle activation than healthy subjects (p<0.0001) and an asymmetric muscle activation with 89.23% muscle balancing for temporals and 83.21% for masseters. The control group showed a 99.32% of muscle balancing for temporals and 97.77% for masseters. These findings suggest that asymmetric muscle activation may influence maxillary and mandibular growth in adolescents with UPCB.