The Effects of the Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) on Osteonecrosis of the Jaw after Bisphosphonate Treatment

Objectives: The defect reconstruction after treatment of advanced stage of bisphosphonate-relate osteonecrosis of the jaw (BRONJ) is challenging. Significant amount of bone and soft tissue deficiency after the treatment and frequent recurrence of necrotic lesion even after the surgical curettage for BRONJ lesion.
The purpose of this study was to evaluate the clinical outcomes after recombinant bone morphogenetic protein-2 (rhBMP-2) for the advanced BRONJ lesion.
Methods: The subject was composed of 16 patients (age range 59 ~ 82) with alveolar bone defects caused by BRONJ (AAOMS stage 2 = 4, stage 3 = 12 ) treatment. The patients were reconstructed with rhBMP-2 combined with hydroxylapatite and were followed up at 1 week, 3 months and 6 months.(KNUH IRB 2013-05-007) The clinical outcome was composed of 1) excellent (full coverage of soft tissue without bony exposure) 2) good (healing in soft tissue completely but there were an initial bony exposure) 3) moderate (almost soft tissue healing but bony exposure exist in some area) 4) poor (no cure in soft tissue and there is extensive bony exposure). Radiographic parameters of bone healing were determined using Halse’s modified radiologic assessment (healing or non-healing, depending on symptom of patients and amount of bone fill).
Results: The results showed excellent soft tissue healing without bony exposure in 12 patients (75%). Dehiscence of the suture were observed initially in 4 patients (25%), but after re-suture, showed good soft tissue healing. The results showed favorable mucosal healing in all patients using the rhBMP-2 combined with hydroxylapatite. Also bony volume was maintained relatively stable in radiographic findings and was showed good results (average amount of graft materials 95%) of treatment in all patients.
Conclusions: It can be concluded that the application of rhBMP-2 combined with hydroxylapatite would be a favorable treatment option for reconstruct alveolar bone defect after BRONJ treatment. The postoperative swelling and wound dehiscence was observed in 25% of the patients, which did not influence the final mucosal healing after the surgery.