Introduction: Oral appliances (OAs) have been widely used to treat snoring and sleep apnea, but their effects on craniofacial structures in patients after 5 years or more of wear have not yet been quantified.
Methods: Seventy-one patients who had worn adjustable mandibular repositioners to treat snoring or sleep apnea were evaluated. Upright lateral cephalometric radiographs in centric occlusion taken before treatment and after a mean of 7.3 +/- 2.1 years of OA use were compared. Baseline sleep studies and patient demographic data were included in the analysis.
Results: Cephalometric analyses after long term OA use showed significant (P < .01) changes in many variables, including increases in mandibular plane and ANB angles; decreases in overbite and overjet; retroclined maxillary incisors; proclined mandibular incisors; increased lower facial height; and distally tipped maxillary molars with mesially tipped and erupted mandibular molars. The initial deep overbite group had a significantly greater decrease in overbite. Duration of OA use correlated positively with variables such as decreased overbite and increased mandibular plane angle; changes in the dentition appeared to be progressive over time.
Conclusions: After long-term use, OAs appear to cause changes in tooth positions that also might affect mandibular posture.