Reinforcing the Mucoperiosteal Pocket with the Scarpa Fascia Graft in Secondary Alveolar Bone Grafting : A Retrospective Controlled Outcome Study

Secondary bone grafting plays an important role in the dental rehabilitation of patients with clefts of the lip, alveolus, and palate. A major complication of this surgical technique is resorption of the grafted bone transplant. Conventional two-dimensional radiographs are often inconclusive and do not demonstrate the true deficit. The main objective of this study was to evaluate the amount and exact location of bone loss on the basis of three-dimensional models over a period of 3 years. Twenty-four patients with unilateral cleft palate were included in this prospective study. Axial computed tomography scans of all patients were taken immediately preoperatively, and 1, 2, and 3 years postoperatively. Volumetric analysis was performed on three-dimensional models of the cleft defects and the bone bridges using three-dimensional computed tomography. All patients were treated by secondary alveolar bone grafting prior to eruption of the permanent canine. Extensive bone resorption was found in the bucco-palatal dimension of the alveolar portion of the transplant. The success rate of secondary bone grafting was high in cases of rapid orthodontic gap closures. The mean bone loss in the first year after surgery was 49.5%. The transplants remained almost constant in the following 2 years. Radiographic scales based on orthopantomography only evaluate the vertical dimension of the transplants. This study, however, showed that bone resorption in the transversal dimension is clearly underestimated with conventional two-dimensional radiographs.

The alveolar cleft in patients with clefts of lip, alveolus and palate (CLAP) is usually reconstructed with an autologous bone graft. Harvesting of autologous bone grafts is associated with more or less donor site morbidity. Donor site morbidity could be eliminated if bone is fabricated by growth factor-aided tissue engineering. The objective of this review was to provide an oversight on the current state of the art in growth factor-aided tissue engineering with regard to reconstruction of the alveolar cleft in CLAP. Medline, Embase and Central databases were searched for articles on bone morphogenetic protein 2 (BMP-2), bone morphogenetic protein 7, transforming growth factor beta, platelet-derived growth factor, insulin-like growth factor, fibroblast growth factor, vascular endothelial growth factor and platelet-rich plasma for the reconstruction of the alveolar cleft in CLAP. Two-hundred ninety-one unique search results were found. Three articles met our selection criteria. These three selected articles compared BMP-2-aided bone tissue engineering with iliac crest bone grafting by clinical and radiographic examinations. Bone quantity appeared comparable between the two methods in patients treated during the stage of mixed dentition, whereas bone quantity appeared superior in the BMP-2 group in skeletally mature patients. Favourable results with BMP-2-aided bone tissue engineering have been reported for the reconstruction of the alveolar cleft in CLAP. More studies are necessary to assess the quality of bone. Advantages are shortening of the operation time, absence of donor site morbidity, shorter hospital stay and reduction of overall cost.

This study compares tissue-absorbed and effective doses of the cone beam CT (CBCT) units, the Veraviewepocs 3D and the 3D Accuitomo, in different protocols. The absorbed organ doses were measured using an anthropomorphic phantom loaded with thermoluminescent dosemeters (TLDs) in 16 sensitive organ sites. Both CBCT units were deployed with different fields of view (FOVs): 3D Accuitomo using two protocols (anterior 4 x 4 cm scan and anterior 6 x 6 cm scan) and Veraviewepocs 3D using three protocols (anterior 4 x 4 cm scan, anterior 8 x 4 cm scan and panoramic + anterior 4 x 4 cm). Equivalent and effective doses were then calculated, the latter based on the International Commission on Radiological Protection's (ICRP) 2005 recommendations. The lowest effective dose was observed for the 3D Accuitomo 4 x 4 cm (20.02 microSv), the highest for the 3D Accuitomo 6 x 6 cm (43.27 microSv). The effective dose recorded for Veraviewepocs 3D was 39.92 microSv for the 8 x 4 cm scan, 30.92 microSv for the 4 x 4 cm scan and 29.78 microSv for the panoramic + 4 x 4 cm scan protocol. The radiation doses delivered by both machines were in comparable ranges when using 4 x 4 cm FOV. A smaller FOV should be used for dental images, whereas a larger FOV should be restricted to cases in which a wider view is required.