Three-dimensional computer-assisted study model analysis of long-term oral-appliance wear. Part 2. Side effects of oral appliances in obstructive sleep apnea patients

Introduction: Oral appliances (OAs) are widely prescribed for the treatment of obstructive sleep apnea (OSA). The occlusal changes that occur after long term OA treatment have not been well described based on detailed computerized three-dimensional (3D) assessment. Methods: Seventy patients with OSA (mean age, 50.0 years) who had been treated with an OA were identified for this study. A MicroScribe-3DX dental study model analysis system was used to make 3D measurements on baseline and follow-up (88.4 ± 26.7 months) study models. Results: The following dental measurements showed significant changes (P <0.05) with long-term use of an OA: mandibular arch width increased more than maxillary arch width, crowding decreased in both arches, the curve of Spee became flat in the premolar area, the mandibular canine to second molar segment moved forward in relation to the maxillary arch, the bite opened and the overjet decreased except in some molar areas. Conclusions: A variety of occlusal changes occur with long-term OA treatment for OSA. The changes could be regarded as either adverse or beneficial depending upon the baseline characteristics.