Computed Tomographic Estimation of Particulate Cancellous Bone and Marrow Weight for Successful Transplant in Unilateral Cleft Lip and Palate Patients

Objective: The defect volume measured on computed tomography (CT) for secondary bone graft (SBG) is well correlated to the actual amount of particulate cancellous bone and marrow (PCBM) transplanted in unilateral cleft lip and palate (UCLP) patients. However, the validity of such measurements have not been completely verified due to lack of evaluation of treatment results. The objective of this study was to propose an estimation method by CT based on the data of successfully treated patients. For this purpose, the association was initially verified between the weight of transplanted PCBM and the defect volume measured on CT using the results of successfully treated patients. Methods: Treatment results were evaluated 1 year after SBG by intraoral radiography in 50 UCLP patients. For the patients with good results, the correlation was investigated between the defect volume on CT and the transplanted PCBM weight, and a method was proposed based on PCBM density, calculated as PCBM weight divided by defect volume on CT. Results: In successfully treated patients showing level 3 or 4 alveolar resorption, a strong correlation (r = .87) was found between the volume on CT and the PCBM weight. Level 4 results were observed in 22 of 23 (95.7%) patients who had calculated PCBM densities of more than 6 g/cm 3. Conclusions: Volume estimation on preoperative CT was confirmed to have sufficient validity. The weight of PCBM transplanted should be greater than the defect volume on CT multiplied by 6.