bruxism

Bruxism is a repetitive jaw-muscle activity characterized by clenching or grinding of the teeth. It can occur during sleep (sleep bruxism) or while awake (awake bruxism). Sleep bruxism often involves rhythmic or nonrhythmic grinding and is associated with arousals during sleep; awake bruxism is frequently linked to concentration or stress and tends to involve more clenching than grinding. The condition is relatively common, with estimates varying by population and diagnostic methods.

Symptoms and consequences range from none to significant. Many people notice tooth wear, flattened chewing surfaces, jaw muscle fatigue, facial or temple soreness, headaches, and temporomandibular joint (TMJ) pain. Chronic bruxism can lead to tooth sensitivity, cracked or fractured teeth, and increased dental-care needs. Some individuals grind at night without awareness, while others may clench or grind during the day.

Causes are multifactorial and not fully understood. Risk factors include psychological factors such as stress, anxiety, and personality traits; sleep disturbances and disorders; genetic predisposition; occlusal or dental factors; and, in some cases, medications such as antidepressants. A combination of central nervous system factors and peripheral influences is thought to contribute.

Diagnosis is usually clinical, based on history and signs such as tooth wear, jaw muscle hypertrophy, and TMJ tenderness. Polysomnography with audio-video and EMG can confirm sleep bruxism in research settings or complicated cases.

Treatment aims to prevent dental damage and relieve symptoms. Approaches include behavioral strategies (stress management, biofeedback, habit reversal), occlusal appliances like night guards or splints to protect teeth, and management of underlying sleep disorders. In rare cases, botulinum toxin injections may be used for severe muscle activity. Prognosis varies; many cases are mild and intermittent, with variable response to treatment.