Linear and Volumetric Radiographic Assessment of Particulate Iliac bone grafts following Secondary Grafting of Unilateral Alveolar Clefts

Background: Particulate autogenous bone grafts remain to be the gold standard for reconstruction of alveolar. The success of alveolar bone grafting is assessed clinically and radiographically. Among the radiographic measures of success is the bone bridging across the cleft, maintenance of the bucco-palatal / vertical linear dimensions of the graft and the stability of the total volume of regenerated bridge of bone. Computed tomography (CT) scans provide a better tool for three-dimensional evaluation of the residual bone following the reconstruction procedure.
Aim of the study: This study aimed at assessing the linear (horizontal, vertical) and volumetric changes that occur in particulate iliac bone grafts 6 months after secondary grafting of unilateral alveolar clefts.
Patients and Methods: Six patients with unilateral alveolar clefts who received particulate autogenous iliac crest grafts were included in this study. On a surgical planning software, their immediate and six-months postoperative CT scans were superimposed onto each other using the cranial base as a reference. On the axial cuts, the linear bucco-palatal dimensions of the reconstructed alveolar cleft were recorded, whereas on the coronal cuts the vertical height of the reconstructed alveolar cleft was measured for both scans. The software was also used to calculate the volume of the bone graft on the immediate postoperative CT and that of the remaining bone graft 6 months after. The data was statistically analyzed in the form of means ± standard deviation and paired T-test used to compare the measurements immediately and six-months postoperatively. The percentage change in the alveolar ridge dimensions over the six months follow up period was then calculated.
Results: The horizontal dimension of the grafted alveolar cleft decreased by an average of 24.4% over the six months period. The difference between the means showed a highly statistically significant difference with a P value < 0.01. While for the vertical dimension, the mean decreased by 21.6% over the six months period and the difference between the means was statistically significant with a P value Conclusions: Radiographic assessment of alveolar cleft reconstruction using CT scans are useful tools, not just for making accurate measurements and better evaluation of the formed bone within the reconstructed alveolar cleft, but also it provides a useful tool for analyzing the outcomes of the secondary alveolar grafting procedure for future correlation and optimization of the whole grafting procedure and expected outcomes.