Sleep bruxism is highly prevalent in adults with obstructive sleep apnea: a large-scale polysomnographic study

The aim was to determine the prevalence and risk factors of sleep bruxism (SB) and to investigate the relationships between SB episodes, arousals, and respiratory events in adults with obstructive sleep apnea (OSA).

This prospective study included 914 adults with OSA (305 females, 609 males; age = 53 years [interquartile range = 17]; apnea-hypopnea index = 13.9 events/h [interquartile range = 21]). The diagnosis of SB was made when the rhythmic masticatory muscle activity (RMMA) index was at least 2 episodes/h of sleep based on a full polysomnographic recording. Binary logistic regression was performed to identify risk factors for SB. Network analysis was performed to determine the relations between RMMA, respiratory event, sleep arousal, and other factors. Further, the percentage of RMMA time-related to arousal was calculated.

The prevalence of SB in adults with OSA was 49.7%. Male sex, lower body mass index, and higher percentage of N1 sleep increased the odds of having SB (odds ratios = 1.425, 0.951, and 1.032, respectively; all P < .05). Network analysis showed that there were no direct associations between RMMA and apnea-hypopnea index, nor between RMMA and arousal, although 85.7% of RMMA was time-related to arousals.

Nearly half of adults with OSA have comorbid SB. Male sex, lower body mass index, and a higher percentage of light sleep increase the risk of having SB. Although RMMAs do not directly correlate with respiratory events and arousals, most RMMAs are time-related to arousals in adults with OSA.

Registry: Netherlands Trial Register; Name: A Large Sample Polysomnographic Study on Sleep Bruxism; URL: https://trialsearch.who.int/Trial2.aspx?TrialID=NL8516; Identifier: NL8516.

Li D, Kuang B, Lobbezoo F, de Vries N, Hilgevoord A, Aarab G. Sleep bruxism is highly prevalent in adults with obstructive sleep apnea: a large-scale polysomnographic study. J Clin Sleep Med. 2023;19(3):443-451.