Dental and skeletal long-term side effects of mandibular advancement devices in obstructive sleep apnea patients: a systematic review with meta-regression analysis

Background: Mandibular advancement devices (MAD) are effective in reducing apnea episodes and they are frequently used as first-line therapy in obstructive sleep apnea (OSA) patients. Objectives: The MAD must be used every night for a lifetime and since it performs its function discharging the forces on dental elements the aim of this systematic review was to identify the dental and skeletal long-term side effects of MAD therapy and to evaluate the influence of time on them in OSA or snoring patients. Search Methods: An electronic search was performed in MEDLINE, Cochrane Database, Google Scholar Beta, Scopus, and LILACS. Studies until 4 April 2018 were analysed, without language restrictions. Selection Criteria: Randomized controlled trials and cohort studies investigating dental and/or skeletal side effects on adult patients wearing MAD for OSA or snoring treatment with at least 2 years follow-up were included and independently evaluated by two investigators. Data Collection and Analysis: The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the risk of bias by means of Cochrane's tools. For each study included and for each dental and/or skeletal parameter, the difference in means and 95% CI was calculated between baseline and follow-up. Results: Twenty-one studies with follow-up between 2 and 11 years were included. The side effects reported were a reduction in overjet, overbite, and in the upper incisor inclination, and an increase in lower incisor inclination, A point-Nasion-B point, and anterior facial height. The meta-regression analysis showed that the side effects were influenced by the therapy duration for all parameters (P < 0.05). The quality of evidence was low/moderate. Conclusions: MAD therapy produces time-related dental and skeletal side effects. After a long period of treatment, the dental side effects are clinically relevant and therefore the clinician should inform the patients about this issue. Since the side effects are progressive, patients need to be continuously monitored over time. Registration: The study protocol was not registered.