Volumetric Assessment of Mandibular Symphyseal Bone graft for Secondary Reconstruction of Unilateral Alveolar Clefts

Purpose: To evaluate the volume of bone graft that can be harvested from the mandibular symphysis and compare it with the bone volume needed for secondary grafting unilateral alveolar clefts using a computer-aided design (CAD) software program based on 3 Dimensional Cone Beam CT Scans. In addition, to study the bone fill of the mandibular symphysis graft in the alveolar cleft.
Subjects & Methods: The subjects were 12 patients with unilateral alveolar clefts who underwent Cone Beam CT Scans 1 week prior to procedure. Using a 3D Analysis Software, the available bone that can be harvested from the mandibular symphysis area was determined using CBCT. Also, the volume of the Alveolar cleft defect was calculated preoperatively to assess the sufficiency of the symphyseal bone graft. All patients underwent secondary alveolar cleft grafting with mandibular symphysis bone. Six months postoperatively, CBCT was used to evaluate the amount of bone fill of the alveolar cleft.
Results: The mean harvestable symphysis bone volume including the lingual cortex was 2.4 cm3 (range: 1.4–4.3 cm3). The actual harvested particulate symphyseal bone graft volume was calculated during surgery and was 2.62 cm3 (range: 1.6–4.0 cm3). The preoperative mean volume of the unilateral alveolar cleft defects was 1.9 cm3 (range: 1.1- 2.85 cm3). The mean postoperative bone fill ratio of the unilateral alveolar cleft was 79% (range 54% to 96%) 6 months postoperatively.
Conclusion: This Study showed that the mandibular symphysis provided sufficient bone volume for secondary unilateral alveolar cleft grafting. Also, the mandibular symphyseal bone graft provided adequate bone fill of the alveolar cleft 6 months postoperatively..