Cleft Width and Secondary Alveolar Bone Graft Success

Abstract

Fifty-six cleft sites were reviewed prior to alveolar bone grafting and subsequently evaluated for graft success using study models, periapical and occlusal radiographs from the Lancaster Cleft Palate Clinic. All patients in this sample had presurgical orthodontics to expand and align the maxillary arch prior to alveolar bone grafting. Ninety-five percent of the grafts were done using iliac crest, the remaining 5% were cranial grafts. The alveolar bone grafting technique used was as described by Boyne and Sands (1972, 1976). Cleft width was measured on a radiograph taken no more than 1 month preoperatively, following the completion of all orthodontic expansion. Cleft width was determined by inspection at its narrowest point. A distortion correction was attempted by determining the ratio of the radiographic width of the maxillary central incisor adjacent to the cleft compared with the actual width of this tooth measured on study models. The radiographic cleft width was then multiplied by this factor to approximate true cleft width. Alveolar contour was measured at least 6 months postoperatively using ratios of actual bone heights measured at the mesial, middle, and distal margin of the previous cleft compared with root length of adjacent teeth. This was to eliminate the radiographic distortion factors of foreshortening and elongation. Regression analysis was carried out to see if there was a correlation between preoperative cleft width and eventual success of the graft as measured on postsurgical radiographs. The success rate for achieving a bony bridge across the cleft was 91%. Mean alveolar crest height achieved was 93% of the anatomic root length of the tooth in the proximal segment and 96% of the anatomic root length of the tooth in the distal segment. There was significant, but low, negative correlation between presurgical cleft width and alveolar bone attachment of teeth adjacent to the grafted cleft site, after a mean radiographic follow-up of 3.1 years. Notching of the alveolar ridge in the region of the bone graft had a statistically significant low positive correlation with differing cleft widths.