Factors related to the efficacy of an adjustable oral appliance for the treatment of obstructive sleep apnea.

AIM: The purpose of this study was to investigate whether any physiological or cephalometric parameters could be used to predict the efficacy of the Klearway oral appliance (OA) for the treatment of obstructive sleep apnea (OSA).

METHODS: Forty-two male and 5 female patients with OSA were recruited on the basis of baseline polysomnography with a documented Apnea and Hypopnea Index (AHI) > 15 per hour. Repeat polysomnography was performed with the appliance in place. Baseline cephalometry was performed for each patient. Subjects were divided into 3 groups on the basis of the degree of change in AHI with OA therapy: good response (> 75% decrease in AHI), moderate response (25% to 75% decrease range in AHI), and poor response (< 25% decrease in AHI).

RESULTS: Patients with a good response were younger and had smaller upper airways. A stepwise regression analysis revealed that a better treatment response with the Klearway appliance was obtained in patients who were younger and had a lower body mass index, a longer maxilla, a smaller oropharynx, a smaller overjet, less erupted maxillary molars, and larger ratio of vertical airway length to the cross-sectional area of the soft palate.