RESUMO
The etiology of bruxism is associated with exogenous factors, such as occlusal interference, stress, and anxiety, as well as endogenous factors involving neurotransmitters of the basal ganglia. Due to the multifactorial etiology of bruxism, interdisciplinary treatment involving professionals from different healthcare fields has been proposed. The aim of the present study was to compare 2 groups of patients with bruxism (11 in each group) treated with either an occlusal splint combined with cognitive behavioral therapy or an occlusal splint alone. Surface electromyography of the masseter and anterior temporal muscles at rest was performed before and after treatment. The mean amplitude of activity of all muscles was lower after treatment, except for the right anterior temporal muscle in the group treated with an occlusal splint alone. Mean amplitudes were greater in the anterior temporal muscles than in the masseter muscles. Significantly greater improvement was found in the group exposed to cognitive behavioral therapy (P < 0.05; analysis of variance and Student t tests). Therefore, the combination of occlusal splint and psychological therapy was more effective at achieving muscle relaxation than occlusal splint use alone.