Effectiveness of Mandibular Advancement Devices in Positional OSA Patients: A Retrospective Analysis of Predictive Variables in a Sample of Adult Patients.

 To evaluate the efficacy of mandibular advancement devices (MADs) in improving apnea-hypopnea index (AHI) in positional obstructive sleep apnea (POSA), compared with a control group of nonpositional OSA (NPOSA) patients, from mild to very severe degree, in order to to find the main variables characterizing the examined group as potential predictors of treatment success.  In the present observational study, we retrospectively collected polysomnographic records of 39 positional adult patients, divided into 30 supine isolated OSA (siOSA) and 9 supine predominant OSA (spOSA) undergoing MADs from 2003 to 2019, and compared with those of a control group of 47 NPOSA patients. Demographics and anthropometrical data, home sleep apnea test (HSAT) records, drug-induced sleep endoscopy (DISE) results, and dental casts evaluation were analyzed pre- and post-treatment with MADs.