Long-Term Effects of Three Different Appliances for Rapid Maxillary Expansion: A Systematic Review and Meta-Analysis.

OBJECTIVE: To compare the long-term effects (≥6 months) of bone-borne (BB) and tooth-BB appliances with tooth-borne (TB) appliances in rapid maxillary expansion. MATERIALS AND METHODS: An electronic search was conducted in PubMed, Cochrane Library, Scopus, Embase, Web of Science, Proquest, ClinicalTrials.gov, and OpenGrey. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to evaluate evidence. Mean differences were calculated, applying a random effects model. RESULTS: Nine studies were included. Six articles were randomized controlled trials (RCTs), two were retrospective studies, and one was a parallel cohort study. Three non-RCTs were at moderate risk of bias. Three RCTs were at unclear risk of bias, while three were at high risk of bias. This review specifically focused on evidence from three-dimensional assessment methods (CBCT/CT). No difference in dental maxillary expansion and skeletal maxillary expansion between appliances, though TB appliances may cause greater molar inclination in the treatment. No differences in buccal bone resorption were observed over a follow-up period exceeding 1 year. CONCLUSIONS: TB, tooth-BB, BB appliances demonstrated comparable long-term effects regarding the amount of dental and skeletal maxillary expansion, molar inclination, and buccal bone resorption.