Safety and Efficacy of Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) in Craniofacial Surgery

Introduction: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is one of the most commonly used osteogenic agents in the craniofacial skeleton. This study reviews the safety and efficacy of rhBMP-2 as applied to craniofacial reconstruction and assesses the level of scientific evidence currently available. Methods: An extensive literature search was conducted. Randomized controlled trials (RCTs), case series and reports in the English language as well as Food and Drug Administration reports were reviewed. Studies were graded using the Oxford Center for Evidence-Based Medicine Levels of Evidence Scale. Data heterogeneity precluded quantitative analysis. Results: Seventeen RCTs (Levels of evidence: Ib-IIb) were identified evaluating the use of rhBMP-2 in maxillary sinus, alveolar ridge, alveolar cleft, or cranial defect reconstruction (sample size: 7-160; age: 8-75 years). Study designs varied in rigor, with follow-up ranging 3-36 months, and outcome assessment relying on clinical exam, radiology, and/or histology. There was wide variation in rhBMP-2 concentrations, carriers, and controls. Most studies evaluating rhBMP-2 for cranial defect closure, mandibular reconstruction, or distraction osteogenesis consisted of retrospective cohorts and case reports. The evidence fails to support RhBMP-2 use in maxillary sinus wall augmentation, calvarial reconstruction, mandibular reconstruction, or distraction osteogenesis. RhBMP-2 may be effective in alveolar reconstruction in adults, but is associated with increased postoperative edema. Conclusions: A risk-benefit ratio favoring rhBMP-2 over alternative substitutes remains to be demonstrated for most applications in plastic and reconstructive surgery. Long-term data on craniofacial growth is lacking, and using rhBMP-2 in patients younger than 18 years remains off-label.