Outcomes of Different Internal Fixation Strategies for Double Mandibular Fractures: A Systematic Review and Meta-analysis.

Background: The biomechanics of double mandibular fracture (DMF) is complex, and the literature on the fixation requirements is varied. The purpose of the study was to estimate the prevalence of complications following the management of DMF and to determine whether this prevalence varies based on the fixation strategy used.

Methods: A systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search was conducted in PubMed, Google Scholar, Semantic Scholar, and Cochrane Library to identify DMF studies until September 2024. Randomized controlled trials (RCTs), quasicontrolled trials, and retrospective studies comparing fixation schemes for DMF were included. In-vitro or animal studies were excluded. The predictor variable was the type of fixation (nonrigid, rigid, and mixed), and outcome variables were malocclusion, wound infection, wound dehiscence, and hardware failure. The risk of bias was assessed using the Joanna Briggs Institute (JBI) checklist for critical appraisal and the Risk of Bias 2.0 generic dataset for RCTs. Meta-analysis was conducted to calculate the pooled prevalence by random effects model with a 95% CI using Stata (v.16).

Results: The initial search identified 2,108 publications. After applying inclusion/exclusion criteria, the final sample was composed of 11 studies and 1,747 cases. The meta-analysis indicated pooled prevalence of 3% (95% CI: 2 to 6%) for hardware failure, 3% (95% CI: 1 to 7%) for malocclusion, 3% (95% CI: 2 to 5%) for wound dehiscence and 4% (95% CI: 2 to 8%) for infection. Complication rates were 4 to 6% (95% CI: 0.01 to 0.05, P = .1) in the nonrigid fixation group, 8 to 12% (95% CI: 0.01 to 0.05, P = .3) in the rigid fixation group, and 2 to 3% (95% CI: 0.01 to 0.05, P = .1) in the mixed fixation group, with no statistically significant subgroup differences. The risk of bias was low (n = 6) and high (n = 1) in retrospective studies, while RCTs (n = 4) showed some bias.

Conclusion: This meta-analysis suggests that the overall complication rate for DMF ranges from 3 to 4%, regardless of the fixation method, and that the type of fixation does not have a statistically significant impact on postoperative complication rates. Further well-designed trials are needed to confirm these findings.