Pharyngeal Airflow Analysis in Obstructive Sleep Apnea Patients Pre- and Post-Maxillomandibular Advancement Surgery

The purpose of this study was to evaluate pharyngeal airflow in obstructive sleep apnea (OSA) patients following maxillomandibular advancement (MMA) surgery using computational fluid dynamics (CFD). Computerized models of four OSA patients, pre- and postsurgery, were created using cone beam computed tomography scans. CFD was used to model airflow at inspiration rates of 340 ml/s, 400 ml/s, and 460 ml/s. The relative pressure, eddy viscosity coefficient, and total area-averaged pressure drops were selected for comparison. Results show a decrease in airway resistance of over 90% for three out of four patients. In these three patients, the MMA surgery reduced the constriction along the airway, which resulted in reduced drag and therefore reduced pressure drop required to move a constant volumetric flow between pre- and postsurgery models. CFD analyses on airways of OSA patients provide data that suggest an improvement in airflow following MMA surgery with less effort required for maintaining constant flow.