Effect of Recombinant Human Bone Morphogenetic Protein on Alveolar Grafting of Cleft Lip and Palate Patients

Secondary reconstruction of the alveolar cleft is usually repaired during the mixed dentition stage between 7 to 11 years of age.  Autologous bone graft from the iliac crest has been the gold standard for many years because it provides osteogenic cells and osteoinductive factors needed for bone healing and regeneration (2). In March 2007 recombinant human bone morphogenetic protein (BMP-2) was approved by the FDA for alveolar ridge augmentation (1).  During the procedure, once the desired alveolar height is achieved, a bovine collagen sponge coated with BMP-2 is placed as a membrane over the iliac crest graft material.  This method holds the graft material in place while simultaneously stimulating chondrogenesis and osteogenesis (1).  These grafting surgeries provide available bone with sufficient soft tissue attachment for future placement of endosteal implants or orthodontic therapy in cases where there is a residual dental space (2).  The participating surgeons estimated that 20% of their cleft lip and palate patients required two or more grafting procedures to repair the alveolar defect.  These patients were being referred back to the oral surgeons, at the time of orthodontic evaluation (~2.37yrs post op) due to deficient alveolar bone support in the cleft site.  The objective of this study was to evaluate whether the number of surgical procedures needed to repair the alveolar cleft decreased by augmenting the graft with BMP-2.  A retrospective chart review was performed as a quality analysis of alveolar cleft surgeries performed by two participating surgeons.  Patients who had alveolar clefts repaired from April 2006 to August 2013 were identified by searching the electronic health records for the CPT code 42210 (palatoplasty with bone graft).  A total of 70 patients met the criteria.  Their charts were reviewed and applicable data were recorded in Excel. The data was analyzed with a t-test, Fisher’s Exact test, and logistic regression.  Of the 70 patients, 45 received ICBG and 25 received ICBG with BMP-2.  The mean age of the ICBG group was 8.87 years vs 9.16 years for BMP-2.  15/45 (33 percent) of patients treated with an ICBG required an additional operation compared to only 4/25 (16 percent) for those treated with BMP-2 (p=0.12).  27% of patients required a second operation deemed necessary for orthodontic treatment (at a mean age 11.38 years) due to inadequate bone support in the cleft site.  The results indicate that the children with ICBG were 2.06 times more likely to need a second surgery than those treated with both ICBG and BMP-2.  Overall, patients with a right unilateral cleft who were treated with BMP-2 had the lowest probability of having a second surgery.  This study supports the potential for BMP-2 reducing the need for additional bone grafting surgery for cleft repair in preparation for orthodontic therapy or implant placement in the cleft site.  This quality analysis indicates that 84% of patient’s who were treated with BMP-2 are successfully treated with one surgery compared to 67% for patient’s treated with iliac crest bone grafting alone.  As a result, the percentage could continue to improve with the use of BMP-2 for alveolar cleft augmentation surgeries.

(1) M.T. van Hout, W. M., Mink van der Molen, A. B., Breugem, C. C., Koole, R., Van Caan, E. M. (2011). Reconstruction of the alveolar cleft: can growth factor-aided tissue engineering replace autologous bone grafting? a literature review and systematic review of results obtained with bone morphogenetic protein-2. Clinical Oral Investigations, 15(3), 297-303. Retrieved from http://link.springer.com/article/10.1007/s00784-011-0547-6/fulltext.html

(2) Cho-Lee, G., García-Díez, E., Nunes, R., Martí-Pagès, C., Sieira-Gil, R., & Rivera-Baró, A. (2013). Review of secondary alveolar cleft repair. Annals of Maxillofacial Surgery, 3(1), 46-50. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3645611/?report=reader