Experimental computer-assisted alloplastic sandwich augmentation of the atrophic mandible

Purpose: This study evaluated the effectiveness of a technique that combine d computer-aided surgery with alloplastic augmentation and implant-borne pr osthodontic rehabilitation of the atrophic mandible. Materials and Methods: Computed tomographic CCT) data from an atrophic cada ver mandible were transferred to a computer-aided design (CAD) system that prepared an anterior sandwich osteotomy. The cranial segment was moved upwa rd and backward to provide an ideal alveolar relationship, and the geometry of the intermediate space was used to design a titanium implant. Furthermo re, a surgical template was derived for the osteotomies, and insertion of d ental implants was planned to stabilize both the transposed bone and the in termediate implant on the bony base. An identical implant for augmentation was also fabricated from poly-D,L-lactide in a mold as a possible resorbabl e carrier for osteoinductive proteins. Results: The experimental surgery was successfully performed with maximum p recision on the dried mandible. The fabrication of an implant made out of p oly-D,L-lactide for the same purpose was also possible. Conclusions: This preliminary experiment showed that, it is possible to use CAD/computer-aided manufacturing (CAM) technology to prepare a prefabricat ed template and a corresponding titanium implant for mandibular augmentatio n with a high degree of exactness. Dental implants could be planned and int egrated in this procedure as well. The fabrication of a mold using this met hod also provided the opportunity to give a complex shape to possible carri ers of osteoinductive substances.