Prevalence of Free Flap Failure in Patients Undergoing Reconstruction for Medication-Related Osteonecrosis of the Jaw: A Systematic Review and Meta-Analysis

<b>Background/Objectives</b>: Medication-related osteonecrosis of the jaw (MRONJ) is a serious complication in patients treated with antiresorptive or antiangiogenic agents, particularly those with cancer-related comorbidities. This systematic review and meta-analysis aimed to estimate the prevalence of free flap failure in patients undergoing microvascular reconstruction for MRONJ. <b>Methods</b>: A comprehensive literature search was conducted across Medline/PubMed, Scopus, and Web of Science up to 30 January 2025. Inclusion criteria were observational studies involving MRONJ patients treated with free flap reconstruction. Risk of bias was assessed using the Newcastle-Ottawa Scale. The pooled prevalence of free flap failure was calculated using a random-effects model with Freeman-Tukey double arcsine transformation. <b>Results</b>: Twelve studies were included in the quantitative analysis. The fibula free flap was the most frequently used flap. The pooled prevalence of free flap failure was 0.1% (95% CI: 0-2.3%), with no significant associations observed in meta-regression analyses for publication year, patient age, or sex. All included studies were of moderate methodological quality. <b>Conclusions</b>: These findings suggest that free flap reconstruction is a reliable and effective surgical option for managing advanced MRONJ in well-resourced and specialized healthcare settings; however, limitations such as small sample sizes and heterogeneity in protocols must be considered. Further high-quality, multicenter studies are needed to evaluate long-term outcomes and refine perioperative management strategies.