Polysomnographic and Electromyographic Evaluation of Sleep Bruxism in Young Colombian Adults: Case-Control Study

Background: Sleep bruxism (SB) is increasingly recognized not merely as a movement disorder but as a multifactorial condition in which physiological, behavioral, and contextual factors converge. Objective: To comprehensively characterize SB in young adults, integrating polysomnography (PSG) and surface electromyography (sEMG) to describe sleep architecture, periodic limb movements (PLMs), and masticatory muscle activity; compare these parameters with matched controls; and explore clinical correlations relevant to dental practice and individualized management. Methods: Forty university adults (20 PSG-confirmed SB; 20 controls) underwent PSG assessment of total sleep time, sleep stages, arousals, apnea, oximetry, and PLMs. EMG activity of the masseter and temporalis muscles was recorded in 37 participants (18 SB, 19 controls). Statistical analyses included t-tests, Mann-Whitney U tests, and multivariate logistic regression to identify independent predictors of SB. Results: SB participants exhibited higher bruxism event counts (p ≤ 0.001; PS = 0.94), increased PLMs (p ≤ 0.01; PS = 0.75), shorter REM sleep duration (p = 0.04; d = 0.69), and higher bruxism-related arousal indices (p ≤ 0.001; PS = 83.4). Left masseter activity differed significantly (p = 0.03; d = 0.50), while other muscle measures showed no significant differences. Logistic regression identified age (OR = 0.59, p = 0.02), PLMs (OR = 0.96, p = 0.03), and REM sleep duration (OR = 0.98, p = 0.05) as independent predictors, explaining 58% of the variance. Conclusions: These findings provide a comprehensive profile of SB in young adults. Integrating PSG, sEMG, and oral assessments supports early diagnosis, personalized management, and interdisciplinary collaboration to prevent complications.