Influence of sleep posture on response to oral appliance therapy for sleepapnea syndrome

Study Objective: This study evaluated the effect of sleep posture on oral a ppliance therapy to elucidate the interindividual difference of response to the device. Design: Seventy-two unselected patients with sleep apnea syndrome were stud ied polysomnographically before and after insertion of the individually fab ricated and adjusted device. Sleep positions were measured using a body pos ition sensor. The patients were classified into three groups; supine, later al and prone groups, according to the position in which apneas were most fr equently observed. Setting: N/A Patients or Participants: N/A Interventions: N/A Measurements and Results: The mean apnea-hypopnea index (AHI) of all patien ts before treatment [43.0 +/- 25.6 (SD)] was significantly (p<0.0001) decre ased after insertion of the appliance (21.6<plus/minus>18.3). The device de creased the mean AHI significantly from 29.8 to 11.3 in the supine position and 5.5 to 1.6 in the prone position, and increased, but not significantly , from 7.7 to 8.7 in the lateral posture. The supine (n=44) and prone (n=13 ) groups showed significant reduction of AHI with the oral appliance, while the lateral group (n=15) revealed only a slight decrease, although not sig nificantly Responders defined by AHI < 10 accounted for 61.4% in the supine group, 0% in the lateral group and 84.6% in the prone group. Responders de fined by a 50% drop in AHI accounted for 84.1%, 6.7%, and 46.7%, respective ly. Conclusions: The effectiveness of oral appliance therapy is greatly influen ced by sleep posture. Sleep posture recorded by polysomnography may be usef ul to predict the future success or failure of the device.