Sleep bruxism

Jamie Harris MD (Dr. Harris of Advocate Health has no relevant financial relationships to disclose.)
Darius A Loghmanee MD (Dr. Loghmanee of Advocate Children's Hospital has no relevant financial relationships to disclose.)
Federica Provini MD, editor. (

Dr. Provini of the University of Bologna and IRCCS Institute of Neurological Sciences of Bologna received speakers' fees from Eisai Japan and Italfarmaco and consulting fees from Zambon.

Originally released July 20, 1994; last updated July 31, 2018; expires July 31, 2021

This article includes discussion of sleep bruxism, bruxism, bruxomania, nocturnal bruxism, nocturnal oral parafunction, nocturnal teeth-clenching, nocturnal teeth-grinding, nocturnal tooth-grinding, rhythmic masticatory muscle activity, and teeth-clenching. The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations.


In this article the authors explain that sleep bruxism is a nocturnal orofacial activity. In sleep medicine, it has been described as a sleep-related movement disorder characterized by simple repetitive movements and transient arousals during sleep. In dentistry, sleep bruxism has been described as a parafunctional activity associated with clenching, bracing, and grinding of the teeth. Because sleep bruxism may provoke destruction of teeth, dental restorations, temporomandibular joint function, and facial pain, dentistry has been more focused on restoring dental work and oral appliances. Although stress has been proposed as a causative factor in aggravating bruxism or being relieved by the bruxism, evidence supports an autonomic imbalance rather than a psychological response. A sequential change from autonomic and brain cortical activities precedes sleep bruxism, suggesting that the central and/or autonomic nervous systems, rather than peripheral sensory factors, have a dominant role in sleep bruxism onset. Also, evidence of underlying genetic links has been proposed. Comorbidities include obstructive sleep apnea, snoring, hypertension, headaches, temporomandibular dysfunction, encephalopathy, epilepsy, affective disorders, psychological stress, and anxiety. At this time, only polysomnographic (PSG) studies can provide a definite diagnosis. Neuroimaging studies provide evidence of functional changes in oral motor cortical areas in patients with bruxism. Treatment of sleep bruxism includes dental orthotics, behavioral modification, medication, and treatment of obstructive sleep apnea.

Key points


• Sleep bruxism is primarily associated with rhythmic masticatory muscle activity (RMMA).


• Bruxism is often reported or observed by sleep partners; self-report has a substantial false-negative rate.


• Obstructive sleep apnea (OSA) is the highest risk factor for sleep bruxism.


• Sleep bruxism is centrally rather than peripherally mediated.


• Treatment is palliative and involves intraoral appliances, behavioral therapies, and medications.

Historical note and terminology

In 1938, Miller introduced the term “bruxism” for bruxomania or repetitive teeth grinding (Miller 1938). One of the first recorded notations of this phenomenon was from Black, who commented, "Abrasion of the teeth may tend to remove the cusps of the teeth quite rapidly” (Black 1886). Later descriptions noted the potential effects of this disorder. In 1941, Bodecker described a patient whose bruxism had destroyed the clinical crowns of all the lower anterior teeth (Bodecker 1941).

Sleep bruxism and diurnal bruxism were not differentiated for several decades; however, the sleep-wake state dependence appears to demonstrate that these are distinct disorders that have different underlying causes and require different treatments.

An international expert consensus examined several definitions of bruxism from sleep medicine and dental organizations and ultimately recommended that bruxism be defined as a repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible (Lobbezoo et al 2013).

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