Comparison of Accuracy in Mandible-First and Maxilla-First Approaches in Bimaxillary Orthognathic Surgery: A Meta-Analysis

This meta-analysis compares the accuracy of mandible-first and maxilla-first approaches in bimaxillary orthognathic surgery to improve clinical decision-making. A systematic search was performed in PubMed, Web of Science, Embase, and Cochrane databases up to August 2024. The analysis included randomized controlled trials and cohort studies with a minimum of 10 patients. Data extraction followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and pooled effect estimates for continuous outcomes were calculated using weighted mean difference (WMD) with 95% CIs. Heterogeneity was assessed using Cochran I2 and Q statistics, with a random-effect model applied when I2 exceeded 50%. Seven studies involving 316 patients were included. The analysis showed no significant differences in vertical (WMD: -0.05, 95% CI: -0.57 to 0.48, P = 0.86), transverse (WMD: -0.17, 95% CI: -0.43 to 0.09, P = 0.21), and sagittal (WMD: -0.41, 95% CI: -0.98 to 0.15, P = 0.15) surgical errors between the two approaches. Rotational surgical errors were also similar, including pitch (WMD: 0.07, 95% CI: -0.11 to 0.25, P = 0.29), roll (WMD: 0.01, 95% CI: -0.18 to 0.25, P = 0.69), and yaw (WMD: 0.12, 95% CI: -0.56 to 0.81, P = 0.72). The findings suggest that there is no significant difference in surgical accuracy between mandible-first and maxilla-first approaches. Therefore, the choice of sequence should be based on patient-specific factors rather than a presumed advantage of one method over the other. Further research, including large-scale randomized controlled trials, is needed to confirm these results and evaluate long-term outcomes.