Association between Sleep Bruxism and Peristalsis of the Esophagus

Objective: It is known that primary peristalsis is the most common motor event in relation to saliva swallowing after gastroesophageal reflux and that secondary peristalsis is also important during sleep when swallowing is suppressed. Recently, we suggested an association between sleep bruxism and saliva swallowing. The purpose of this study was to examine the relationship between sleep bruxism and peristalsis. Methods: Seven adult volunteers were studied. We measured the masticatory muscle activity (EMG), orofacial movements, and pressure of the middle and lower esophagus during sleep. Using the EMG and audiovisual data, we scored bruxism episodes according to the research criteria of Lavigne et al. Primary and secondary peristalsis episodes were scored according to each individual's peristalsis pattern. The relationship between sleep bruxism and peristalsis episodes was statistically analyzed. Results: There was a significant correlation between the frequency of sleep bruxism and primary peristalsis episodes. The duration from sleep bruxism to primary peristalsis was significantly shorter than that from peristalsis to the next sleep bruxism. However, there was no positive correlation between sleep bruxism and secondary peristalsis. Sleep bruxism did not occur during secondary peristalsis episodes. Conclusion: The results suggest that the occurrence of sleep bruxism is closely associated with primary peristalsis.