Predictors of Outcomes in 900 Alveolar Bone Grafts

Background: Significant discrepancies exist in the reported variables influencing alveolar bone graft outcomes. The purpose of this study was to evaluate graft success and identify outcome predictors in a large patient cohort using an objective cone beam computed tomography assessment tool. Methods: Consecutive patients with cleft lip/palate who underwent alveolar bone grafting by 1 surgeon were included. Predictor variables were age at graft, oronasal fistula, canine position, concurrent premaxillary osteotomy, size of cleft, presence of bony palatal bridge, history of failed graft, location of primary repair, and surgeon experience. The outcome variable was graft success, determined using a cone beam computed tomography assessment tool and defined as a score of 3 or 4 (out of 4) in the following domains: vertical bone level, labiopalatal thickness, and nasal piriform symmetry. Results: The sample included 900 alveolar cleft sites (median graft age, 9.9 years). The success rate was 94.6%. Presence of an erupted canine, large cleft defect, or premaxillary osteotomy were independent predictors of graft failure; presence of a bony palatal bridge was associated with graft success ( P < 0.05). Conclusions: Presence of an erupted canine, large bony defect, or premaxillary osteotomy increase the risk of failure, and a bony palatal bridge portends success. Age 12 years or older, visible oronasal fistula, history of failed graft, primary cleft repaired at outside institution, and surgeon experience were associated with higher graft failure, but were not independent predictors when controlling for covariates. Surgeons should be aware that these factors in combination increase the odds of graft failure. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.