Daytime Sleepiness and Dispositional Optimism Are Related to Awake Bruxism Among Patients With Painful...

Awake bruxism (AB) is a multifactorial condition that has been linked to several physiological and psychological factors. The aim of this study was to investigate the potential association between AB-related behaviours, daytime sleepiness, and dispositional optimism.

A cross-sectional study was conducted at the Academic Centre for Dentistry Amsterdam (ACTA). Participants with pain-related temporomandibular disorders (TMD) that worsened with function were included. The survey comprised subjective assessment of the frequency of AB-related oral behaviours (items adopted from the Standardised Tool for the Assessment of Bruxism, STAB), anxiety and depression (Patient Health Questionnaire-4, PHQ-4), daytime sleepiness (Epworth Sleepiness Scale, ESS), and dispositional optimism (Revised Life Orientation Scale, LOT-R). Spearman's rank correlation and Mann-Whitney U tests were used for bivariate analysis. Ordinal logistic regression was conducted to determine the associations between AB behaviours, ESS and LOT-R while controlling for age, sex, smoking status, anxiety and depression.

A total of 1661 patients were included, with a mean age of 42 years, of whom 77.6% were women and 84.2% were nonsmokers. Bivariate analyses showed significant associations between the frequency of AB-related oral behaviours, ESS and LOT-R. In the regression models, daytime sleepiness was found to be associated with increased frequency of teeth grinding, clenching and contact, but not with mandible bracing. Dispositional optimism was associated with a lower frequency of teeth grinding. Although statistically significant, the observed associations reflected small effect sizes.

This study demonstrates an association, albeit with a small effect size, between the frequency of certain self-reported AB behaviours and both daytime sleepiness and dispositional optimism. These findings suggest that, while these factors may play a modest role, they deserve consideration as potential contributors to the report of AB.