[Sandwich osteotomy--a biologic method for vertical augmentation of edentulous alveolar ridges].

Vertical augmentation for rehabilitation with dental implants poses a clinical challenge. The surgical obstacles have been extensively documented within the literature. Outcomes of the multiple methods available are not predictable, and overall success rates are sub-optimal. This paper presents the Sandwich Osteotomy Technique (interpositional rhBMP-2 and bone subtitute grafting) in a young female with congenital oligodontia. The uniqueness of this method, like in distraction osteogenesis, is that the segmental bone remains attached to the mucoperiosteal flap and thus the blood supply is maintained. Bone graft or substitute is introduced into the interpositional space that was created. Advantages of Sandwich Osteotomy are minimal bone exposure, good blood supply, no need for donor bone graft and minimal overall morbidity. Limitations of the technique are soft tissue stretching, gingival fibrosis, and high technical demand. According to our experience with this surgical method, vertical augmentation is stable up to 8 mm. Beyond this height approximately 10% bone resorption was noticed.