Accuracy of Computer-Aided Design/Computer-Aided Manufacturing Surgical Template for Guidance of Dental Implant Distraction in Mandibular Reconstruction With Free Fibula Flaps.

Abstract

The direction and orientation of the osteotomized upper segments in dental implant distractor (DID) can be compromised due to an unpredicted vector of distraction. The present study aimed to evaluate the accuracy of computer-aided design/computer-aided manufacturing (CAD/CAM) surgical templates to precisely guide the distraction process in lengthening of the alveolar height for functional mandibular reconstruction. This retrospective study included all consecutive patients who underwent digitally designed mandibular reconstruction using the fibular flap and DID with the help of CAD/CAM designed surgical templates in a single-stage procedure from 2011 to 2014. First, the preoperative digital planning was performed on 3-dimensional models. Afterward, simulation of the distraction process was made on the virtual model and the resulting new height of the fibula was evaluated. The preoperative simulation was applied to accurately define the exact location and path of the DID device to achieve the suitable vertical height. The preoperative digital planning was used to help the design of the CAD/CAM surgical template, which was then fabricated by means of the 3-dimensional printing technology. The manufactured surgical template-assisted both horizontal and vertical osteotomies of the fibular segments and defining the DID path to lead the distractor into the accurate position. The outcome evaluation was achieved through comparing both preoperative virtual planning with postoperative actual outcomes. This study included 14 subjects, 8 were males and 6 were females. The mean age at time of surgery was 31.07 years (range 18-47). All fibular flaps showed 100% success rate. The mean vertical bone height attained with the DID device was 11.35 mm. The vertical and horizontal osteotomies of the fibular segments were completed, then the DID devices were successfully positioned guided by the template. The mean values of the linear and angular deviations for the distractor position and upper segments were calculated and recorded. The maximum linear deviation between the virtual and the postoperative actual distractors was 0.93 mm in the anteroposterior direction, and the greatest in the horizontal plane was 4.64°. CAD/CAM surgical templates can accurately guide the direction and orientation of the DID device for functional mandibular reconstruction; therefore, helping to improve the outcomes by accurately transferring the preoperative virtual plan to real surgical procedure.