MASTICATORY MUSCLE FUNCTIONS FOLLOWING ANTERIOR BITE PLANE THERAPY IN GROWING PATIENTS WITH SKELETAL CLASS II MALOCCLUSION

Abstract

This study evaluated changes in several masticatory muscle activities following anterior bite plane (ABP) therapy in growing patients with skeletal Class II malocclusion using surface electromyography. Surface electromyographic recordings were performed to assess temporalis anterior (TA) and masseter muscle (MM) activity during rest, maximum voluntary clenching (MVC), and chewing before and after ABP therapy. Parameters included muscle activity, bilateral symmetry, muscle synergy coordination, and relative muscle effort. Results showed overbite reduction after treatment. Non-significant changes (p > 0.05) in resting muscle activity and MVC were observed in both muscles (p > 0.05). Slight increases in TA and MM activity during chewing were detected, despite their non-significances (p > 0.05). Muscle symmetry during MVC and chewing remained stable following treatment, with non-significant changes in TA and MM synergy. Muscle synergy and occlusal units remained stable throughout the treatment period and among all patients following treatment, respectively. These findings indicated that ABP therapy effectively reduces deep bite while maintaining normal neuromuscular function and coordination in growing patients with skeletal Class II malocclusion.