Anteroinferior distraction of the atrophic subtotal maxillary alveolus for implant placement: a case report.

Most reports on alveolar distraction have been related to vertical distraction in the mandible and the maxilla. There have been few reports on horizontal or oblique alveolar distraction. A case of an atrophic subtotal maxillary alveolus distracted 10 mm anteriorly and 5 mm vertically, followed by the placement of 9 implants, is presented. A healthy, 55-year-old woman presented with a chief complaint of mobility of all maxillary teeth. All remaining 11 teeth except the maxillary left second molar were diagnosed as being involved with advanced marginal periodontitis, and were considered hopeless and subsequently extracted. Three months after extraction, a horizontal osteotomy was performed with a bone saw between the bilateral second premolar regions, extending vertically distal to the second premolars, without involving the maxillary sinuses. After confirming mobility of the alveolar bone, a distraction device was seated with titanium miniscrews and adhesive resin cement over the hard palate. After a 7-day waiting period, the maxillary alveolus was distracted anteroinferiorly 0.25 mm twice a day for 25 consecutive days. The distraction process was completed uneventfully. Postdistraction computed tomography demonstrated that the maxillary alveolus was adequately distracted to place implants in an ideal position. Nine endosseous implants were placed 4 months after seating the distraction device. All implants had good primary stability and were submerged. All implants osseointegrated, although 2 anterior implants were replaced due to disintegration resulting from transmucosal overloading of the interim removable prosthesis. No significant marginal bone resorption was seen around the implants 16 months after implant placement. It was concluded that alveolar distraction can be very useful for augmenting the atrophic alveolus, not only vertically but also horizontally or obliquely.

Recombinant human bone morphogenetic protein-2 promotes osteogenesis within atelopeptide type I collagen solution by combination with rat cultured marrow cells.

We evaluated the combination effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) and cultured rat bone marrow mesenchymal stem cells (MSCs) in atelopeptide type I collagen (AC) solution on osteogenesis in a diffusion chamber (DC) to develop a bone substitute having consistent osteogenic capability for clinical applications. The cultured MSCs were obtained by 10-day primary culture of fresh bone marrow cells of Fischer rats. We prepared three groups of DCs: AC solution with rhBMP-2, AC solution with cultured MSCs, and AC solution with rhBMP-2 and cultured MSCs. The prepared combined solutions were injected into DCs, which were subcutaneously implanted into the backs of syngeneic rats. DCs were harvested after 2, 4, or 8 weeks and analyzed for bone-forming capability by determining histological and osteoblastic biochemical markers. De novo bone formation was observed both inside and outside of the membrane filter of DCs in the group of AC solution with rhBMP-2 and cultured MSCs. The alkaline phosphatase activity and osteocalcin content in the group of AC solution with rhBMP-2 and cultured MSCs were significantly higher than those in the group of AC solution with cultured MSCs at any time. These findings indicate that AC aqueous solution is a useful material not only as a carrier of rhBMP-2 but also as a cell-anchorage for differentiation and proliferation of MSCs. Therefore, this study suggests that clinical repairs of bone defects are feasible using injectable AC solution with rhBMP-2 and cultured MSCs as a bone substitute.