The Effect of Positional Dependency on Outcomes of Treatment With a Mandibular Advancement Device

OBJECTIVE: To evaluate retrospectively the efficacy of the mandibular advancement device (MAD) in patients with obstructive sleep apnea in terms of positional dependency. DESIGN: Retrospective analysis. SETTING: Academic tertiary referral center. PATIENTS: One hundred patients with obstructive sleep apnea treated with the MAD at the Department of Otorhinolaryngology sleep clinic were included from January 1, 2005, through December 31, 2010. INTERVENTIONS: All patients underwent nocturnal full-night polysomnography before and at least 3 months after intraoral MAD application. MAIN OUTCOME MEASURES: Treatment results and prognostic factors deciding the success of MAD application. RESULTS: Of the 100 patients, 80 showed positional dependency and 20 showed nondependency. In the position-dependent obstructive sleep apnea group, the median (interquartile range) apnea-hypopnea index (AHI) decreased from 32.1 (24.4-41.9) to 8.6 (3.7-13.8) (P < .001); in the nondependent group, from 56.4 (26.2-71.5) to 15.7 (6.8-30.7) (P < .001). The success rate (AHI reduction ≥50% and AHI <10) was 57.5% and 30.0% in position-dependent and position-nondependent groups, respectively (P = .04). CONCLUSION: Identifying patients with obstructive sleep apnea as position dependent or nondependent may have important therapeutic implications in predicting the outcome of MAD treatment.