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.