MANDIBULAR MORPHOLOGY AND THE EFFICACY OF A MANDIBULAR ADVANCEMENT DEVICE IN PATIENTS WITH SLEEP-APNEA

The aim of the present study was to evaluate whether the outcome of tr eatment using an intraoral mandibular advancement device in patients w ith obstructive sleep apnoea is associated with the mandibular morphol ogy. The effects of the device on apnoeas and sleep were evaluated in 32 men with obstructive sleep apnoea in continuous polysomnographic sl eep recordings including body position, during one night without the d evice and one night with it. Mandibular morphology variables were meas ured on cephalograms. The odds ratio for a supine apnoea-hypopnoea ind ex of below 15 during treatment was 17 for a mandibular plane angle of 38 degrees or below, and 26 for a lower anterior face height of less then 73 mm. The outcome of treatment in the lateral sleep position was unrelated to any mandibular morphology variable. Patients with supine -dependent sleep apnoea defined by a supine apnoea-hypopnoea index of 10 or above and a lateral apnoea-hypopnoea index of below 10 had an od ds ratio of 7 to have an orthognathic mandible with an SNB angle of 78 degrees or above. The present study suggests that a successful apnoea reduction using a mandibular advancement device is associated with a normal mandibular plane angle and a small lower anterior face height.