Volumetric Assessment of Resorption Patterns of Bilateral Alveolar Clefts in Cone-Beam Computed Tomography in Two-Stage Bone Graft

Objective: Few studies have analysed the outcome of bone grafts in bilateral alveolar clefts and the bone fill with a two-step surgery method. The currently applied three-dimensional method used in this study enables a comprehensive description of the bone fill of bilateral clefts after bone grafting. The study aimed to describe alveolar cleft volume and bone fill after alveolar bone grafting of bilateral alveolar clefts treated with two-step bone grafting, with a comparison between the first and the second bone graft site. A secondary aim was to investigate whether the cleft volume on the non-surgical side changed after contralateral surgery. Materials and Methods: In this retrospective study, 60 CBCT scans from 20 patients were included (8 girls and 12 boys) with an age range of 6.5-11.5 years (mean age 8.7). The cleft volume was measured in pre- and post-operative CBCT scans and assessed in ITK-SNAP to calculate the bone fill of the cleft. Results: After bone grafting, 47% of the first bone-grafted cleft was filled with bone, and 33% of the second bone-grafted cleft, without significant difference between them (p = 0.03). The mean preoperative cleft volume was 0.42cm(3) and the mean residual cleft volume after bone graft was 0.23cm(3). There was however a significant difference when comparing the bone fill between the nasal and the dental part (p < 0.001). Conclusion: Almost half of the cleft volume was filled with bone after bone grafting. The order of the bone graft side did not influence the bone fill of the cleft.