Effect of Progressive Mandibular Advancement on Airway Size

This technical report investigates the effect of progressive mandibular advancement on pharyngeal airway size in anesthetized adults. The study involved nine healthy adult volunteers who underwent magnetic resonance imaging (MRI) during wakefulness and intravenous propofol anesthesia. The objective was to determine how varying degrees of mandibular advancement influence airway dimensions. The participants were fitted with a custom oral appliance to facilitate mandibular advancement. Measurements of airway area and diameters were taken under different conditions: without advancement, at 50% maximum advancement, and at maximum advancement. Results indicated that airway area decreased during anesthesia without mandibular advancement compared to wakefulness. However, maximum mandibular advancement during anesthesia restored airway size to levels observed during wakefulness. The findings suggest that maximum advancement is necessary to maintain pharyngeal airway dimensions during anesthesia, which is critical for preventing airway obstruction in clinical settings.