The efficacy of oral appliances in the treatment of severe obstructive sleep apnea

Objectives: The purpose of this study is to evaluate the efficacy of oral appliance (OA) treatment for subjects with severe obstructive sleep apnea (OSA) and to determine the dental parameters associated with treatment outcomes. Study design: This study uses a prospective longitudinal design. Methods: Consecutive Chinese subjects with severe OSA who refused continuous positive airway pressure treatment were recruited. Their dental measurements were taken from lateral cephalometric radiographs. Polysomnograms with OA were repeated at 3 months and 1 year. Blood pressure was taken in the morning after sleep studies. Results: Thirty-four subjects were evaluated at 3 months and 1 year according to the principle of intention-to-treat analysis. OA reduced AHI significantly in subjects with favorable responses, from 49.3 (37.4-67) to 12.5 (6.1-15.7), p<0.001 at 3 months and from 47.5 (41.1-72.9) to 13.1 (6.0-14.0), p<0.001 at 1 year. These OSA subjects had an increased overjet at baseline compared to those with unfavorable responses (p≤0.05). Systolic blood pressure was significantly reduced in those hypertensive OSA subjects after 3 months and 1 year of treatment. Conclusions: OA reduces the severity of sleep apnea, and the effect is maintained at 1 year in subjects with retrognathism. OA appears to reduce systolic blood pressure in hypertensive OSA subjects at 3 months and 1 year.