Bone-Borne Maxillary Expansion and Traditional Rapid Maxillary Expansion: A Systematic Review and Meta-Analysis

Introduction: The aim of this study was to perform a systematic review and meta-analysis to compare the effect of bone-borne expansion (BBE) and tooth-borne expansion (TBE) in patients with maxillary constriction. Methods: Electronic databases, including MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials, were searched up to February 2019. Eligible clinical trials and cohort studies that studied the effects of bone-borne and tooth-borne expansion appliances on patients with constricted maxilla were selected. The study selection, data extraction, and risk of bias assessment were independently performed by two authors. Then, the random-effects meta-analysis and post-hoc heterogeneity tests were performed.  Results: In the end, four studies were included in the present meta-analysis (i.e., a randomized clinical trial, two prospective controlled clinical trials, and a cohort study) that collected data from 117 patients. The mean differences between TBE and BBE were 0.38 mm and -0.28 mm for premolar and molar apices, 0.67 mm and 1.18 mm for premolar and molar crowns, 0.19 mm and 0.17 mm for alveolar bone in premolar and molar areas, and -0.61 mm and 0.02 mm for nasal and maxillary bones, respectively. Moreover, the differences between TBE and BBE for dental angulation were 3.84◦ and 1.52◦ for left and right molars, as well as 4.85◦ and 3.46◦ for left and right premolars, respectively. Conclusion: The BBE appliances do not have any advantages over tooth-borne devices with regard to the amount of skeletal or dental expansion; however, it seems to produce less tipping in posterior teeth.