Long-term sequellae of oral appliance therapy in obstructive sleep apnea patients: Part 2. Study-model analysis

Introduction: Side effects observed in the occlusion and dental arches of patients using an oral appliance (OA) to treat snoring or sleep apnea for more than 5 years have not yet been investigated. Methods: Stone casts trimmed in centric occlusion before appliance placement and after an average of 7.4 +/- 2.2 years of CA use in 70 patients were compared visually by 5 orthodontists. Results: Of these patients, 14.3% had no occlusal changes, 41.4% had favorable changes, and 44.3% had unfavorable changes. Significant changes in many variables were found. Patients with greater initial overbites and Class II Division 1 and Class II Division 2 malocclusions were more likely to have favorable or no changes. More favorable changes in overbite occurred in subjects with large baseline overbites. A greater baseline overjet and more distal mandibular canine relationship were correlated to favorable changes. A greater initial overjet was correlated to a more favorable change, a decrease in mandibular crowding, a smaller change in anterior crossbite, and a greater change in overjet. Conclusions: CA wear after a mean of 7.4 years induces clinically relevant changes in the dental arch and the occlusion.