Early postoperative evaluation of secondary bone grafting into the alveolar cleft and its effects on subsequent orthodontic treatment

Background : Alveolar bone grafting is a standard procedure used to achieve good occlusion for both functional and aesthetic purposes in patients with cleft lip and palate. At the past, main methods used to evaluate bone bridge formation after bone grafting are radiographs, such as dental, occlusal, and panoramic. Purpose : To evaluate bone bridge both qualitatively and quantitatively, we used CT scans (conventional and QCT). Quantitative computed tomography (QCT) has previously been used for measuring bone mineral density of the lumbar vertebrae. Patients and methods : The study comprised 26 male and 15 female patients who underwent alveolar bone grafting. We analyzed bone bridge with regard to four factors : marginal bone level, vertical height, anteroposterior bone width and bone mineral density using dental radiographs, and CT scans such as conventional and QCT. The clinical results of orthodontic treatment were evaluated more than 2 years postoperatively. Results : Orthodontic treatment was considered to be successful when the bone bridge satisfied the following criteria : marginal bone level≧3, vertical height≧6.5 mm, anteroposterior bone width≧5 mm, and bone mineral density<350 mg Ca5 (PO4) OH/mL. Conclusion : we could predict the prognosis of patients’ orthodontic treatment in early stage after bone grafting.