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.