A Comparative Study of EMG Biofeedback and Pharmacotherapy for the Treatment of Masticatory Muscle Hyperactivity in Bruxism Patients

Bruxism is a movement disorder characterized by excessive activity of the masticatory muscles, resulting in teeth clenching and grinding. It affects 50% to 95% of the adult population. Unlike normal, voluntary chewing movements associated with eating, bruxism involves involuntary jaw muscle contractions that cause tension, leading to muscle soreness and pain. Common symptoms include localized muscle tenderness, orofacial pain, anxiety, stress, fatigue, headaches (especially in the temporal region), restricted mouth opening, and temporomandibular joint stiffness. These symptoms can disrupt sleep, causing transitions from deep to light sleep, increased micro-arousals, and sleep fragmentation, leading to daytime fatigue that impacts social life and work performance.

Bruxism can also lead to masticatory muscle hypertrophy (especially the masseter), tongue burning, linea alba on the cheeks, excessive tooth wear, damage to dental prosthetics, changes in saliva secretion, severe craniofacial pain, and TMJ stiffness. Common treatments for bruxism-related pain often involve medications like Botox, clonazepam, or diazepam, but these are typically temporary and do not address the underlying causes. Moreover, long-term use of these medications may cause complications, and their high cost can limit accessibility.

Non-pharmacological treatments for bruxism include biofeedback, muscle relaxation exercises, occlusal splint therapy, and psychotherapy. Biofeedback, which provides real-time information on bodily functions, helps individuals recognize and modify harmful behaviors. Electromyography (EMG) biofeedback, recognized as effective for temporomandibular disorders (including bruxism), is endorsed by the American Association of Psychophysiology and Biofeedback (AAPB) as an evidence-based intervention.

This study aims to compare the effects of EMG biofeedback training versus oral medications in reducing masticatory muscle hyperactivity in bruxism patients, focusing on addressing the underlying pathophysiology, a topic that, to the authors' knowledge, has not been explored in previous research.