Effectiveness of mandibular advancement devices in the treatment of obstructive sleep apnea and the impact of different body positions on treatment: A systematic review and meta-analysis

Objective: The meta-analysis aimed to evaluate the efficacy of mandibular advancement device (MAD) for the treatment of obstructive sleep apnea (OSA) and explore the effect of different positions on MAD for OSA. Methods: The Embase, PubMed, Medline, and Cochrane Library databases were searched for relevant studies evaluating the effect of MAD on the treatment of OSA from database inception to November 2022. The Bayesian random-effects mode was used to calculate the pooled outcome. Subgroup analysis and sensitivity analysis were applied to investigate the heterogeneity. Results: A total of 6 studies enrolling 643 patients were eligible for further analysis. MAD treatment led to improvements in total apnea-hypopnea index (AHI) for both positional OSA(POSA) and Non-POSA groups, but there was no significant difference in the effect of MAD on Non-POSA and POSA (MD = - 1.46,95%CI [-4.89,1.97], P = 0.40). In the supine position, AHI improvement after MAD treatment in POSA group was more than that in Non-POSA group by 15 events/hour in average (MD = 14.82, 95%CI [11.43,18.22], P<0.00001), while in the non-supine position, the change of AHI in Non-POSA group was significantly better than that in POSA group by approximately 8 events/hour (MD = -7.55,95%CI[-10.73,-4.38],p < 0.00001). Conclusion: MAD is more suitable for POSA compared to Non-POSA in patients with habitual sleep in the supine or supine predominant position. While for patients with habitual sleep in the non-supine position, MAD is an effective treatment option for Non-POSA.