0588 RELATIONSHIP BETWEEN PHARYNGEAL VOLUME AND APNEA HYPOPNEA INDEX AFTER MAXILLOMANDIBULAR ADVANCEMENT SURGERY IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA

Abstract Introduction: The obstructive sleep apnea (OSA) is a progressive disease and that is gaining great attention of the health area due to the serious co-morbidities associated to it. Several works in the literature have pointed maxillomandibular advancement (MMA) as the most effective surgical treatment for OSA, with success rates of 96 to 100, but there are important aspects in the evaluation of this surgery that need to be further clarified. The objective of this study was to assess the volumetric anatomical changes of the pharynx after MMA surgery and its repercussions in Apnea Hypopnea Index (AHI). Methods: Thirty-two patients with a polysomnographic diagnosis of OSA participated in the study and where submitted to polysomnography (PSG) and image acquisition by Computed Tomography (CT). Polysomnography and CT were performed preoperatively (T0) and six months after MMA (T1). The pharyngeal air space of the region between the hard palate and he base of the epiglottis was divided into a retropalatal (RP) region and a retrolingual (RL) region. The comparison between preoperative and postoperative data was performed using Student’s t-test for paired samples (paired t-test). Results: Postoperative CT showed a mean volumetric increase of 37,6% in the RP region and of 38% in the RL region. The mean value of preoperative AHI was 34,5 events per hour of sleep, presenting a significant (p