Accuracy of a new custom-made bone-supported osteotomy and repositioning guide system for reconstruction of the mandibular ramus using costochondral grafts: a preliminary study.

Mandibular reconstruction in patients with hemifacial microsomia is still challenging. In this study we have introduced a costochondral graft (CCG) for reconstruction of the mandibular ramus, and reported a bone-supported osteotomy and repositioning guide system for transfer of a virtual plan. Fourteen young children with Pruzansky type III hemifacial microsomia were included and treated with CCG to reconstruct the ramus. We first made 3-dimensional models for virtual planning and simulation, with calculations for both the position and direction of the CCG, to achieve optimal morphology. We did an osteotomy and manufactured them using a 3-dimensional printing technique. Accuracy was evaluated by comparing the plan with the postoperative outcomes. The largest linear root-mean-square deviation (RMSD) between the planned and the postoperative CCG was 4.41mm in the anteroposterior direction, while the largest angle RMSD was 19.25° in the horizontal plane. We suggest that the accuracy of this new custom-made guide system is clinically acceptable for transferring the position and direction of the CCG.
(Copyright © 2019. Published by Elsevier Ltd.)