A new method for computer-aided operation planning for extensive mandibular reconstruction.

Reconstruction of the mandible is challenging, because of the mandible’s significant effect on facial harmony and its central role in mastication, speech, swallowing, and tongue base support necessary to maintain a patent airway.1–3 The aims of mandibular reconstruction are to facilitate a satisfactory facial appearance and to provide suitable conditions for subsequent oral rehabilitation with dental prostheses. In mandibular reconstruction using bone grafts, the functional and aesthetic outcomes are definitely influenced by the position and shape of the graft. Therefore, preoperative planning is important and focuses on the extent and shape of the defect, the positional relationship between the maxilla and the mandible, and the correct position of the condyle in the glenoid fossa. These factors ultimately define the graft design and configuration. The most common method of preoperative planning is three-dimensional representation and simulation using rapid prototype models created from preoperative computed tomography scans.4–9 However, these models simply demonstrate the preoperative condition. The entire preoperative planning process is carried out using the stereolithographic model. One disadvantage of this system is that simulation surgery, including cutting procedures, can be performed only once. From the practical point of view, it would be ideal if various scenarios for reconstruction could first be tested on a computer using preoperative computed tomography data. The rapid prototype model showing the final expected postoperative result could then be made afterward. For this purpose, our department has developed a new computer-based planning program using a computed tomography dataset. With this method, the entire preoperative planning process is fully integrated in a computeraided design procedure that can be performed on a common computer workstation. This planning method was designed for clinical application. We therefore attempted to apply the planned scenario developed in the virtual simulation surgery to the real operation. In this report, we provide a detailed description of our new computer-assisted planning method for extensive mandibular reconstruction.