Sleep Bruxism in Respiratory Medicine Practice Pierre Mayer, MD; Raphael Heinzer, MD; and Gilles Lavigne, DMD, PhD Sleep bruxism (SB) consists of involuntary episodic and repetitive jaw muscle activity charac- terized by occasional tooth grinding or jaw clenching during sleep. Prevalence decreases from 20% to 14% in childhood to 8% to 3% in adulthood. Although the causes and mechanisms of idiopathic primary SB are unknown, putative candidates include psychologic risk factors (eg, anxiety, stress due to life events, hypervigilance) and sleep physiologic reactivity (eg, sleep arousals with autonomic activity, breathing events). Although certain neurotrans- mitters (serotonin, dopamine, noradrenalin, histamine) have been proposed to play an indirect role in SB, their exact contribution to rhythmic masticatory muscle activity (RMMA) (the elec- tromyography marker of SB) genesis remains undetermined. No specific gene is associated with SB; familial environmental influence plays a significant role. To date, no single explanation can account for the SB mechanism. Secondary SB with sleep comorbidities that should be clinically assessed are insomnia, periodic limb movements during sleep, sleep-disordered breathing (eg, apnea-hypopnea), gastroesophageal reflux disease, and neurologic disorders (eg, sleep epilepsy, rapid eye movement behavior disorder). SB is currently quantified by scoring RMMA recordings in parallel with brain, respiratory, and heart activity recordings in a sleep laboratory or home setting. RMMA confirmation with audio-video recordings is recom- mended for better diagnostic accuracy in the presence of neurologic conditions. Management strategies (diagnostic tests, treatment) should be tailored to the patient’s phenotype and comorbidities. In the presence of sleep-disordered breathing, a mandibular advancement appliance or CPAP treatment is preferred over single occlusal splint therapy on the upper jaw. CHEST 2016; 149(1):262-271 KEY WORDS: sleep apnea; sleep arousal; sleep bruxism; sleep disordered breathing; tooth grinding Sleep bruxism (SB) is an involuntary trigeminal motor activity characterized by episodic and repetitive jaw muscle activity with occasional tooth grinding or jaw clenching during sleep. By consensus, SB has been defined as repetitive jaw muscle activity characterized by clenching or grinding of the teeth and bracing or thrusting of the ABBREVIATIONS: EMG = electromyography; GERD = gastroesopha- geal reflux disease; PSG = polysomnography; RBD = rapid eye movement behavior disorder; REM = rapid eye movement; RERA = respiratory effort-related arousal; RMMA = rhythmic masticatory muscle activity; SB = sleep bruxism; SDB = sleep-disordered breathing; TMD = temporomandibular disorder AFFILIATIONS: From the Department of Medicine (Dr Mayer), Pul- monology and Sleep Clinic, Centre Hospitalier de l’Université de Montréal, Montreal, QC, Canada; Center for Investigation and Research in Sleep (Dr Heinzer), University Hospital of Lausanne, Lausanne, Switzerland; and Faculty of Dental Medicine and Centre for Advance Research in Sleep Medicine (Dr Lavigne), Hôpital du Sacré- Coeur, Université de Montréal, Montreal, QC, Canada. FUNDING/SUPPORT: The research of Dr Lavigne is supported by the Canada Research Chair Program, the Canada Institutes of Health Research, and the Fonds de Recherche du Québec–Santé/Quebec Pain Research Network as well as the Ronald Denis Trauma Foundation, Montreal, QC, Canada. CORRESPONDENCE TO: Pierre Mayer, MD, CHUM-Hôtel-Dieu, 3840 St-Urbain, Montreal, QC H2W 1T8, Canada; e-mail: pierre.mayer@ umontreal.ca Copyright Ó 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved. DOI: http://dx.doi.org/10.1378/chest.15-0822 [ Contemporary Reviews in Sleep Medicine ] 262 Contemporary Reviews in Sleep Medicine [ 149#1 CHEST JANUARY 2016 ]