“A Novel Non-invasive Patient-specific Navigation Method for Orbital Reconstructive Surgery: A Phantom Study using Patient Data.”

Background: The correction of orbital deformities is an ongoing challenge in maxillofacial surgery. Computer-assisted navigation can improve surgical outcomes. However, conventional registration methods for navigation are not appropriate for orbital reconstructive surgery. This study proposes an accurate, noninvasive, patient-specific navigation method and demonstrates its feasibility. Methods: A noninvasive, patient-specific registration frame based on the external auditory canals and upper front teeth was designed using in-house developed software. A three-dimensional (3D) craniofacial model was segmented from patient computed tomography (CT) data for the registration frame. A customized craniofacial phantom was also made using this 3D model, with 20 embedded target points on the orbital model and 21 landmark points on the reference standard model. The proposed method was compared with two conventional registration methods: the dental splint-based method and the invasive marker frame-based method. Twenty trials were conducted for evaluation. Target registration error (TRE) and surface registration error (SRE) were computed to measure accuracy. Results: The proposed method showed a TRE of 1.05±0.52 mm, with greater accuracy than conventional methods (dental splint: 2.10±0.63 mm, invasive marker frame: 1.22±0.46 mm). The proposed method yielded the best results for SRE, with 0.38 mm of deviation (dental splint: 0.82 mm, invasive marker frame: 0.60 mm). Conclusions: The proposed noninvasive, patient-specific registration method demonstrated superior results for both TRE and SRE, compared to other conventional registration methods for computer-assisted navigation in orbital reconstructive surgery. Financial disclosure Statement: This work has been supported by the KIST Institutional program (2V05810, 2E27990). This study was also supported by a grant (16-724) from the Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea. Acknowledgement: This work was supported by the KIST Institutional program (2V05430). This study was also supported by a grant (16-724) from the Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea Co-Corresponding authors: Jong Woo Choi, MD, PhD, MMM, Professor, Department of Plastic and Reconstructive Surgery, Biomedical Engineering Research Center, University of Ulsan College of Medicine, Seoul Asan Medical Center, Address: 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea; Tel.: +82-2-3010-3604, E-mail: pschoi@amc.seoul.kr Youngjun Kim, PhD, Principal Researcher, Center for Bionics, Korea Institute of Science and Technology, Address: 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea. Tel.: +82-2-958-5606, E-mail: junekim@kist.re.kr ©2018American Society of Plastic Surgeons

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