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.
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.
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).
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.

Obstructive sleep apnea syndrome (OSAS) is the most common breathing-related sleep disorder. It is characterized by recurrent episodes of partial or complete airway obstruction during sleep, resulting in a reduction in or the total cessation of airflow, despite ongoing respiratory efforts, leading to oxygen desaturation and arousal. The purpose of this literature review is to evaluate the most common characteristics of this pathology, as well as to investigate the most effective treatment options, providing an update on the management of OSA patients.

The purpose of this work was to present a review of the literature concerning obstructive sleep apnea syndrome, and the role of the dentist in this pathology, both to identify elements useful for a good diagnosis and to apply the available therapeutic strategies. In literature there is no unanimous opinion on the treatment of OSAS. The multidisciplinary approach is necessary, creating teams made up of dentists, otolaryngologists and medical experts in sleep disorders, in order to develop a cooperation-based treatment plan for the disease. In this review, the importance of early diagnosis, orthodontic therapy in order to restore normal function is underlined, since OSAS is linked to a high risk of hypertension, cardiovascular diseases, daytime sleepiness, domestic and work accidents, with consequent deterioration of the quality of life.