Sleep bruxism

Federica Provini MD (

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.

Clarissa Drumond PhD (

Dr. Drumond of Faculdade Santa Maria, Brasil has no relevant financial relationships to disclose.

Junia Maria Serra-Negra PhD (

Dr. Serra-Negra of Universidade Federal de Minas Gerais, Brasil, has no relevant financial relationships to disclose.

Originally released July 20, 1994; last updated October 27, 2020; expires October 27, 2023


Sleep bruxism is a repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible. 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, according to the current international consensus, sleep bruxism has been described as a behavior. As for consequences, sleep bruxism may provoke tooth wear, fracture of restorations, temporomandibular disorder, headache, and muscular orofacial pain. Dental therapy involves palliative procedures such as protective plates and care for the temporomandibular joint, in addition to multidisciplinary care for associated factors. There is controversy among researchers about the association between emotional factors and bruxism. However, systematic reviews have proven that emotions act as a trigger for bruxism. 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. Therefore, the association between malocclusions and poorly adapted dental restorations was ruled out as being a peripheral factor. Comorbidities include snoring, hypertension, headaches, temporomandibular disorder, encephalopathy, epilepsy, affective disorders, psychological stress, personality traits, and anxiety. At this time, the diagnosis of definitive bruxism is made with polysomnography or with electromyography, associated with clinical signs of the stomatognathic system and the patient's self-report. Neuroimaging studies provide evidence of functional changes in oral motor cortical areas in patients with bruxism. Treatment of sleep bruxism includes dental plates, behavioral modification, and medication.

Key points


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


• Bruxism is often reported or observed by sleep partners; self-reporting has a substantial false-negative rate. The clinical signs of the stomatognathic system associated with polysomnography or EMG are important.


• Snoring, sleeptalking, and nightmares are factors associated with 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

The allusion to grinding and clenching of teeth comes from ancient times, mentioned in the Bible in gospels such as Luke 13:28, Matthew 13:41-2, Matthew 8:12, Matthew 13:50, Matthew 22:13, and Matthew 24:51. 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 that "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 awake 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 (Lobbezoo et al 2018).

An international expert consensus examined several definitions of bruxism from sleep medicine and dental organizations and 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). In the most recent publication of the international consensus, experts defined bruxism as a behavior (Lobbezoo et al 2018).

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