Dentoskeletal changes of long-term oral appliance treatment in patients with obstructive sleep apnea: A systematic review and meta-analysis.

Purpose: This systematic review and meta-analysis aimed to evaluate the dental and skeletal effects of the long-term oral appliance (OA) treatment in patients with obstructive sleep apnea (OSA) and provide insights for clinicians in treatment planning and decision-making for OSA patients undergoing OA treatment.

Materials and methods: A comprehensive literature search was conducted in major databases up to April 2024. Studies were included if they assessed long-term OA treatment (≥6 months) in adults with OSA using any type of mandibular advancement device (MADs) or tongue retaining device (TRD). Dental and skeletal changes, measured by dental cast and cephalometric analysis, were the primary outcomes.

Results: A total of 42 studies were included in the systematic review, with 23 included in the meta-analysis. Long-term OA treatment was associated with a significant decrease in overbite (0.87 mm, 95% CI: 0.69-1.05) and overjet (0.86 mm, 95% CI: 0.69-1.03). Subgroup analyses showed the decrease of overbite and overjet progressively changed over the years intervals. There was a significant retroclination of the upper incisors (U1-SN, 2.58°, 95% CI: 1.07-4.08) and proclination of the lower incisors (L1-MP, -2.67° (95% CI: -3.78-1.56). Skeletal changes were not significant.

Conclusion: Overbite and overjet gradually decreased in the long-term OA treatment, which might predominantly result from the retroclination of the upper incisors and the proclination of the lower incisors. The skeletal patterns in the anteroposterior and vertical direction might remain relatively stable over time. There was a tendency for the clockwise rotation of the mandible.