Effects of primary alveolar bone grafting on maxillofacial development in the rabbit

Unilateral maxillary clefts were created in 4-week-old rabbits by removing premaxillary-maxillary sutures. Four groups, five animals per group, were formed. Control animals (Group I, no clefts) helped determine normal values for facial growth. In Group II the clefts were unrepaired. In Group III each had a rib graft harvested and placed into the alveolar defect only. In Group IV the cleft was completely grafted with multiple ribs to the nose. At six months postoperatively skeletons of all animals were directly measured and an orthogonal coordinate analysis compared maxillary and palatal growth among groups. Greatest deviations in growth were seen when the entire cleft was grafted; shortened maxillary development and nasal deflection to the clefted side occurred. Unrepaired clefts and grafts limited to the alveolus had maxillofacial development similar to that in unoperated controls. The location of grafts in clefts in infancy appears critical to avoid retarded maxillary growth.