Mandibular advancement devices decrease systolic pressure during the day and night in patients with obstructive sleep apnea: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to analyze whether or not mandibular advancement devices (MADs) produce changes in blood pressure in patients with obstructive sleep apnea (OSA) in relation to use time and if the device is used at night or day. Materials and method A systematic review of the literature and meta-analysis was carried out in accordance with PRISMA guidelines. In the bibliographic search, a total of four databases were consulted: PubMed-Medline, Scopus, Web of Science, and Cochrane. Of the 622 articles initially revealed, 160 duplicates were eliminated. After applying the selection criteria, 17 articles were included for the qualitative analysis and 4 for the meta-analysis. The studies were combined using a random effects model with the inverse method of variance, determining the mean differences in systolic and diastolic pressure before and after treatment using the MAD splint as the effect size. Day/night circadian effect and treatment time were analyzed using meta-regression with a mixed-effects model. Results MAD treatment was not found to affect diastolic pressure. By combining the four studies with the control group in a meta-analysis ( I 2 = 75%; z = − 0.15; p -value = 0.882), the mean difference in diastolic pressure between the MAD group and the control group was estimated at − 0.06 (− 0.86; 0.74). The meta-regression also showed no significant effect of day/night ( p = 0.560) or treatment time ( p = 0.854) on diastolic pressure. When combining the four studies with the control group ( I 2 = 84%%; z = − 1.47; p -value = 0.142), a non-significant mean difference in systolic pressure between the MAD group and the control group of − 0.99 (− 2.31; 0.33) was estimated in the meta-analysis. However, when assessing the effect of day/night or treatment time on systolic blood pressure using a meta-regression, the latter showed significant covariates that reduce systolic blood pressure values in the model at night ( p < 0.001) and in relation to treatment time ( p < 0.001). Conclusions Only systolic pressure appears to be affected by the use of the MAD in patients with OSA, and this decrease in systolic pressure is greater at night and when treatment time is longer.