Mid-Term Outcomes, Biological Responses and Complications of Dental Implants in Maxillomandibular Reconstruction with Free Bone Flaps: A Systematic Review and Meta-Analysis

<b>Background/Objectives:</b> Maxillofacial reconstruction with a vascularized free bone flap for facial contour restoration serves as a foundation for dentition rehabilitation. Although state-of-the-art studies have reported promising results with implant-supported prostheses in such cases, evidence for dental implant prognosis remains insufficient. This study aims to synthesize the mid-term clinical outcomes of implants placed in vascularized free bone flaps, taking into account the biological responses and associated complications. <b>Methods:</b> Studies with a minimal 3-year follow-up, no less than 10 patients, and reporting implant survival/success rate were included. Literature published from 2000 to 2025 was collected from PubMed, Embase, and Scopus. Meta-analyses were performed to pool the implant survival and success rates for the entire cohort, the biological complication rates, the odds ratio for radiotherapy, and the pooled implant failure rates associated with radiotherapy. Parameters related to biological prognosis were collected. ROBINS-E and NOS scale were used to assess the risk of bias. <b>Results:</b> Of the 949 records identified, 14 retrospective and 2 cohort studies were included, yielding a total of 1165 dental implants placed in free bone flaps. On the implant level, meta-analysis demonstrated a pooled implant survival rate of 97.9% (95% CI: 0.922-0.994, <i>I</i>² = 64.4%) and a pooled implant success rate of 88.1% (95% CI: 0.803-0.931, <i>I</i>² = 68.3%). The pooled biological complication rate was 8.6% (95% CI: 0.052-0.138; <i>I</i>² = 69.5%). Among patients who underwent radiotherapy, the pooled implant failure rate was 13.7% (95% CI: 0.087-0.210; <i>I</i>² = 0.0%; <i>p</i> = 0.4702) with an odds ratio of 3.086 (<i>I</i>² = 66.5%) for radiotherapy-associated implant failure. <b>Conclusions:</b> Implant-related outcomes in these complex cases are generally acceptable, with high survival, moderately high success rates and overall stable biological response. Additionally, radiotherapy adds to the risk of implant failure on implant level. However, the statistical heterogeneity and inconsistent definitions of biological outcomes in the literature suggest that caution is warranted when planning implant therapy in these cases. Further studies with long-term follow-up, focused on peri-implant tissue conditions and adopting more stratified study designs to minimize confounding factors, are needed.