Drug-induced sleep endoscopy (DISE) represents an opportunity to evaluate the upper airway in sleep-like conditions. In its current clinical form, however, DISE does not routinely determine the functional impact of anatomic and neuromuscular factors on airflow obstruction. The investigators will apply nasal pressure (CPAP) during DISE to generate pressure-flow and pressure-area relationships, deriving functional determinants of upper airway obstruction during sleep. In addition, they will use objective anatomic measurements from computerized tomography (CT) and submental ultrasound. The findings will allow the investigators to streamline the upper airway exam during DISE, and will further the goal of developing personalized solutions that address specific pathogenic mechanisms of pharyngeal collapse and airflow obstruction during sleep. The investigators will use the physiologic and anatomic features derived from DISE and imaging to determine which are predictive of success to standard-of-care surgical interventions (e.g. skeletal, soft tissue, neurostimulation) .