Oral appliance titration and nasal resistance in nonapneic subjects

Abstract

Initial mandibular position might be a key factor leading to rapid therapeutic outcome in oral appliance therapy for patients with obstructive sleep apnea (OSA). The purpose of this study was to investigate the effects of an adjustable oral appliance on nasal resistance in 7 nonapneic patients. Upright and supine nasal resistance was measured for each subject with an adjustable oral appliance in place in 3 mandibular positions: most retruded (MAX 0), maximum protrusion (MAX 100), and 67% of MAX 100 (MAX 67). A significant decrease in upright and supine nasal resistance was observed between MAX 0 and MAX 67 ( P < .01), and between MAX 0 and MAX 100 ( P < .01), but not between MAX 67 and MAX 100. In addition, there was a positive correlation between the nasal resistance at MAX 0 and the nasal resistance change from MAX 0 to MAX 67 ( P < .01), indicating that when the mandible was advanced from MAX 0 to MAX 67, the more nasal resistance at MAX 0, the greater the reduction in nasal resistance at MAX 67. These findings suggest that MAX 67 might be indicated as the initial mandibular position and that gradual anterior titration of mandibular position beyond MAX 67 would give OSA patients rapid therapeutic effects by reducing the nasal resistance. Moreover, OSA patients with augmented nasal resistance at MAX 0 might have a greater reduction in nasal resistance in response to MAX 67 in oral appliance therapy.