BACKGROUND
    Although numerous techniques have been described to address the cleft palate surgically, none has addressed the lack of bone in the anomalous hard palate.
    Unlike the soft palate, which is normally repaired in three layers, hard palate defects are usually covered with an unnatural and boneless soft tissue layer. The lack of bone puts children with cleft palates at risk of developing abnormal palatal growth, oronasal fisulization, and dento-alveolar collapse following primary palatoplasty. The ideal hard palate repair would provide not only soft tissue support, but also a bony scaffold layer to act as a buttress for the palatal arches to prevent hourglass deformities and other forms of collapse.
    A novel approach to cleft palate repair is hereby described, utilizing recombinant human bone morphogenetic protein-2 (rhBMP-2) at the time of primary palatoplasty. The aim of this technique is to promote bone formation in the hard palate after cleft surgery, to restore the natural intraoral architecture for a longer-lasting operative result.
METHODS
    Five (n=5) patients with unilateral nonsyndromic cleft palates were selected from a patient database at Joe DiMaggio Children Hospital’s Cleft and Craniofacial Center. A retrospective chart review was conducted after obtaining institutional review board approval.
    All patients underwent one-stage palatoplasty using a modification of the Von Langenback technique. The procedure calls for placement of 3mg of rhBMP2 (Medtronic Sofamor Danek, Memphis, TN) and 1.5g of allogenic cancellous bone chips (Community Tissue Services, Dayton, OH) in the central hard palate, between the closed nasal mucosa suture line and bilateral mucoperiosteal flaps. The lateral donor-site defects are covered with Tisseal glue (Baxter Healthcare, Deerfield, IL).
    Patients were evaluated clinically at follow-up visits to determine the quality of the soft tissues. Additionally, computed tomography (CT) scans were obtained for all patients on postoperative day one as well as several months after surgery (range, 4-13 months). Volumetric quantification of osseous tissues between the superior alveolar ridges was performed on all images. Data from both sets of images were statistically compared utilizing paired t-test analysis.
RESULTS
    All patients recuperated well from surgery and were discharged home within two days of their operation. Outpatient follow-up was conducted at regular intervals, with the longest visits done 4 to 10 months after surgery (mean, 7.6 months). Parents reported improved feeding and weight gain for all patients in the study. Oral examinations revealed oronasal fistulization rate of 0/5 (0%), infections in 0/5 (0%), and ectopic bone formation in 0/5 (0%) patients. Subjectively, all surgical wounds were found to be healing appropriately.
    Follow-up CT scans demonstrated increased bone generation across the hard palate defect when compared to initial CT images. Volumetric measurement data comparison revealed statistically significant hard palate ossification (p=0.015, CI=95%) and a 56% mean increase of palatal bone deposition (SD+/-12.7). New bone was detected on all images spanning the hard palate defect and bridging the superior alveolar ridges. No ectopic bone formation was appreciated.
CONCLUSIONS
    This is the first report in the literature citing the use of rhBMP-2 with palatoplasty to address the cleft hard palate defect. Our observations indicate this novel approach produces significant bone growth in the hard palate with no adverse effects in the short term. This procedure aims to lessen the need for further interventions stemming from soft tissue breakdown or palatal arch collapse. It is our hope that normal restoration of the bony architecture of the hard palate will ensure proper growth and development over time.
    Despite our encouraging findings, this study is limited by the lack of long-term follow-up and a small study population. Prospective, randomized studies are necessary to determine the long-term repercussions rhBMP2 may have on maxillary growth and development; particularly in terms of ectopic bone formation, midface hypoplasia and speech formation.