Mixed Reality and 3D Printed Models for Planning and Execution of Face Transplantation

Abstract
Objective: The aim of this study was to evaluate a novel holographic craniofacial surgical planning application and its implementation throughout the planning and operative stages of facial transplantation by performing a critical analysis of comparative utility, cost, and limitations of MR and 3D printing. Summary of Background Data: Face transplantation is a highly complex form of craniofacial reconstruction requiring significant planning, knowledge of patient-specific spatial relationships, and time-sensitive decision making. Computer-aided 3D modeling has improved efficiency and outcomes of complex craniofacial reconstruction by enabling virtual surgical planning and 3D printed model generation. MR technology can enhance surgical planning, improve visualization, and allow manipulation of virtual craniofacial biomodels within the operative field. Methods: Accounting for the time-sensitive nature of face transplantation, a unique, highly coordinated workflow for image acquisition and processing was designed to facilitate rapid holographic rendering and 3D printing. During recent face transplantation, both holographic and 3D printed models were utilized, and the time and cost of fabrication were compared. Results: Holographic models required less time and cost for fabrication. They provided both comprehensive visualization of 3D spatial relationships and novel means to perform VSP and virtual face transplantation by interacting with and manipulating patient-specific, anatomic holograms. Conclusion: Time efficiency, low-cost biomodel production, provision of unlimited preoperative surgical rehearsal, and potential for intraoperative surgical guidance makes holographic VSP and MR highly promising technology for use in complex craniofacial surgery.