RhBMP-2 in the Reconstruction of Alveolar Clefts as an Alternative to Autologous Grafting

Abstract

Background: Secondary alveolar cleft reconstruction using autologous anterior iliac crest (AIC) is currently the gold standard treatment. Although highly predictable and successful, this additional surgical site is associated with considerable, although rare, donor site morbidities including significant postoperative pain, potential for infection, as well as gait and neurosensory disturbances. In an effort to minimize the morbidities associated with autologous graft surgery, a variety of grafting alternatives have been explored, including the use of recombinant human bonemorphogenetic protein (rhBMP-2) on an absorbable collagen sponge (ACS). Bone morphogenetic protein is an osteogenic growth factor essential for embryologic development and formation of the skeleton. Minute quantities of these proteins are contained in the mature skeleton and are involved in bone healing and remodeling throughout life. When administered at a supraphysiologic level, bone morphogenic protein is found to be a potent inducer of de novo bone generation. INFUSE (Medtronic, Minneapolis, MN) is FDA approved for certain spinal fusion and maxillofacial procedures. In recent years, off-label use for alveolar cleft repair in pediatric patients has shown to be an effective and feasible alternative technique in the reconstruction of alveolar cleft defects. Methods: A chart review was conducted of 8 patients whounderwent secondary alveolar cleft reconstructionusing INFUSE (rhBMP-2/ACS) by a single surgeon (DCH). 3 females and 5 males were identified with age at time of treatment ranging from 7 to 13 years and an average age of 9.8 years. Of the 8 patients, 6 had unilateral alveolar cleft defects and 2 had a bilateral defects repairedwith a total of 10 sites grafted. Post-operative i-CAT (Imaging Sciences International, LLC, Hatfield, PA) cone beam CT scans were taken at aminimumof sixmonths following graftingprocedures to assess success of bone formation at the alveolar cleft. Success was measured by evaluating bone height fromnasal floor to alveolar crest,width, bone density using Hounsfield unit (HU), and radiographic evidence of bony continuity.