Application of spiral computed tomography to evaluate the autogenous grafted bone in unilateral complete cleft lip and palate patients following early orthodontic tooth movement

Abstract

Objective The purpose of this study was to evaluate the outcome of autogenous bone grafts in unilateral cleft lip and palate patients following early orthodontic tooth movement,and to determine the volume of new bone formation in the bone grafted region with spiral computed tomography.Methods Computed tomography scans of 12 patients were taken immediately preoperatively and at 6 months postoperatively.The patients underwent bone grafting between 9 and 13 years of age were divided into two groups based on whether postoperative orthodontic tooth movement were initiated or not.Three-dimensional models were created in each period,and the defect of alveolar cleft and volume of the newly formed bone were calculated in each patient.The roots of the moved teeth and their positions to the alveolar bone were also observed.Results The preoperative cleft width and cleft volume were not significantly different between both groups.The volume of the newly formed bone in group A was (0.98±0.23) mm3,significantly higher than that in group B,which was (0.73± 0.15) mm3.The rate of newly formed bone in group A was (72.5 ± 11.9)％,significantly higher than that in group B,which was (53.2±9.7)％.The cleft adjacent teeth could move smoothly into the bone grated area,with no root resorption observed in the computed tomography scans.Conclusions Early orthodontic tooth movement can reduce bone resorption in autogenous bone grafted unilateral cleft lip and palate patients through the observation of spiral computed tomography.It plays an active role in the bone remolding process after bone grafting. Key words: Cleft alveolar; Autogenous bone graft; Orthodontic tooth movement; Spiral computed tomography