A New Technique for Sandwich Osteoplasty with Interpositional Bone Grafts for Fixation

Purpose: To present a new technique for sandwich osteoplasty in the posterior mandible and to evaluate its feasibility as part of dental implant treatment. Materials and Methods: A retrospective study of sandwich osteoplasty in the posterior mandible was conducted. No osteosynthetic material was used to stabilize the osteotomy. Fixation was achieved with the interposition of two bone blocks harvested from the retromolar region. Results: Eighteen patients with 26 sites of severe atrophy of the posterior mandible were treated. After a healing period of 4 months, 53 dental implants were inserted into the augmented region. The implants were loaded with single crowns or fixed dental prostheses 3 months after placement. The mean vertical bone gain after 4 months of healing was 4.2 mm (standard deviation 1.4 mm). The average bone loss between augmentation and implantation was 2.3 mm (35.4%). All implants osseointegrated and showed no clinical signs of peri-implantitis. In three subjects, the elevated bony segment perforated the lingual mucosa near the adjacent teeth after excessive elevation (> 6 mm) but healed without any sequelae. Conclusion: An alternative method for vertical alveolar ridge augmentation of the posterior mandible is presented. No osteosynthetic material is required for fixation, and related complications can be avoided. Further prospective clinical studies are required to demonstrate the feasibility of this technique versus the conventional sandwich osteoplasty. Keywords: dental implants, mandibular augmentation, sandwich osteoplasty, vertical ridge augmentation