The effects of mandibular advancement appliance therapy on jaw-closing muscle activity during sleep in patients with obstructive sleep apnea: A 3-6 months follow-up

Study Objectives: The main aim of this study was to investigate the effects of mandibular advancement appliance (MAA) therapy on jaw-closing muscle activity (JCMA) time-related to respiratory arousals, and on JCMA time-related to nonrespiratory arousals in patients with obstructive sleep apnea. Methods: Eighteen patients with OSA (mean ± standard deviation = 49.4 ± 9.8 years) with a mean ± standard deviation apnea-hypopnea index of 22.0 ± 16.0 events/h of sleep participated in a randomized controlled crossover trial in which two ambulatory polysomnographic recordings, 1 with an MAA in situ and another without the MAA in situ, were performed. JCMA was quantified as the sum of rhythmic masticatory muscle activities and other orofacial activities. Results: Significant reductions in the apnea-hypopnea index (Z = −2.984; P =.003), in the respiratory arousal index (Z = −2.896; P =.004), and in the JCMA time-related to respiratory arousal index (Z = −3.434; P =.001) were found with MAA in situ. On the nonrespiratory arousal index, and on the JCMA time-related to nonrespiratory arousal index, MAA had no significant effect (T = 2.23; P =.82; and Z = −0.66; P =.51, respectively). Conclusions: This study shows that effective mandibular advancement appliance therapy significantly reduces jaw-closing muscle activities time-related to respiratory arousals in OSA patients. Future studies are needed to confirm these findings in obstructive sleep apnea patients with comorbid sleep bruxism.