• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.381-389
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• 2013

Two patients with partial edentulous maxilla were scheduled to undergo installation of implant fixtures using a tooth-supported surgical template based on computer assisted treatment planning. After 3-dimensional (3D) computed tomographic scanning was transferred to the OnDemand3D (Cybermed Co., Seoul, Korea) software program for virtual planning, fixtures of MK III Groovy RP implant of the Br${\aa}$nemark System (Nobel Biocare AB Co., G$\ddot{o}$teborg, Sweden) was installed using the In2Guide (CyberMed Co., Seoul, Korea) tooth-supported surgical template with a Quick Guide Kit (Osstem Implant Co., Seoul, Korea) system in the posterior maxilla of each patient. Sinus floor elevation with a xenogenic bone graft procedure was also performed simultaneously in one patient. Fixture installations were completed successfully without complications, such as sinus mucosa perforation, bony bleedings, fenestrations, or others. During the last two-year follow-up period after prosthetics delivery, each implant was found to be fine with no other minor complications. The entire procedures are reported and the literatures on use of tooth-supported surgical template was reviewed.

• Journal of International Society for Simulation Surgery
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• v.3 no.2
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• pp.69-73
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• 2016

Traditionally 2D cephalometric analysis has been used for diagnosis and treatment of maxillofacial deformities. However, 2D has some limitations in diagnosis and treatment planning especially facial asymmetry cases. The most weakness of 2D is overlapping and unpredictability. Today 3D treatment tools are used by many maxillofacial surgeons. 3D treatment tools can show ungarbled facial anatomy and do virtual surgery. The aim of this report is to present usefulness of using 3D analysis and virtual orthognathic surgery for severe facial asymmetry patients.

• Journal of International Society for Simulation Surgery
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• v.4 no.1
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• pp.9-12
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• 2017

Purpose Surgery for separating craniopagus twins involves many critical issues owing to complex anatomical features. We demonstrate a 3D printed model and virtual reality (VR) technologies that could provide valuable benefits for surgical planning and simulation, which would improve the visualization and perception during craniopagus surgery. Material & Methods We printed a 3D model extracted from CT images of craniopagus patients using segmentation software developed in-house. Then, we imported the 3D model to create the VR environment using 3D simulation software (Unity, Unity Technologies, CA). We utilized the HTC Vive (HTC & Valve Corp) head-mount-display for the VR simulation. Results We obtained the 3D printed model of craniopagus patients and imported the model to a VR environment. Manipulating the model in VR was possible, and the 3D model in the VR environment enhanced the application of user-friendly 3D modeling in surgery for craniopagus twins. Conclusion The use of the 3D printed model and VR has helped understand complicated anatomical structures of craniopagus patients and has made communicating with other medical surgeons in the field much easier. Further, interacting with the 3D model is possible in VR, which enhances the understanding of the craniopagus surgery as well as the success rate of separation surgery while providing useful information on diagnosing and surgery planning.

• The Journal of Korea Robotics Society
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• v.17 no.1
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• pp.8-15
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• 2022

In this paper, we proposed the method of virtual reality-based surgical navigation to reproduce the pre-planned position and angle of the pedicle screw in spinal fusion surgery. The goal of the proposed method is to quantitatively save the surgical plan by applying a virtual guide coordinate system and reproduce it in the surgical process through virtual reality. In the surgical planning step, the insertion position and angle of the pedicle screw are planned and stored based on the virtual guide coordinate system. To implement the virtual reality-based surgical navigation, a vision tracking system is applied to set the patient coordinate system and paired point-based patient-to-image registration is performed. In the surgical navigation step, the surgical plan is reproduced by quantitatively visualizing the pre-planned insertion position and angle of the pedicle screw using a virtual guide coordinate system. We conducted phantom experiment to verify the error between the surgical plan and the surgical navigation, the experimental result showed that target registration error was average 1.47 ± 0.64 mm when using the proposed method. We believe that our method can be used to accurately reproduce a pre-established surgical plan in spinal fusion surgery.

• The korean journal of orthodontics
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• v.51 no.5
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• pp.321-328
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• 2021

Objective: To examine the accuracy of computer-aided intraoperative navigation (Ci-Navi) in bimaxillary orthognathic surgery by comparing preoperative planning and postoperative outcome. Methods: The study comprised 45 patients with congenital dentomaxillofacial deformities who were scheduled to undergo bimaxillary orthognathic surgery. Virtual bimaxillary orthognathic surgery was simulated using Mimics software. Intraoperatively, a Le Fort I osteotomy of the maxilla was performed using osteotomy guide plates. After the Le Fort I osteotomy and bilateral sagittal split ramus osteotomy of the mandible, the mobilized maxilla and the distal mandibular segment were fixed using an occlusal splint, forming the maxillomandibular complex (MMC). Real-time Ci-Navi was used to lead the MMC in the designated direction. Osteoplasty of the inferior border of the mandible was performed using Ci-Navi when facial symmetry and skeletal harmony were of concern. Linear and angular distinctions between preoperative planning and postoperative outcomes were calculated. Results: The mean linear difference was 0.79 mm (maxilla: 0.62 mm, mandible: 0.88 mm) and the overall mean angular difference was 1.20°. The observed difference in the upper incisor point to the Frankfort horizontal plane, midfacial sagittal plane, and coronal plane was < 1 mm in 40 cases. Conclusions: This study demonstrates the role of Ci-Navi in the accurate positioning of bone segments during bimaxillary orthognathic surgery. Ci-Navi was found to be a reliable method for the accurate transfer of the surgical plan during an operation.

• The Journal of the Korean dental association
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• v.50 no.11
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• pp.660-669
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• 2012

We describes the process of 3D virtual treatment planning and of CAD/CAM for surgical splint in orthognathic surgery. The potential benefits and disadvantages of 3D virtual approach and the use of CAD/CAM system for the treatment of the patient with a maxillofacial deformity are discussed. For the more convenient applications,3D software should be improved.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.158-165
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• 2011

A 73-year-old Korean female patient with a fully edentulous mandible was planned to have five implant fixtures installed in the anterior mandible for the fixed prosthesis. After 3-dimensional (3D) computed tomographic scanning was transferred to OnDemand3D$^{(R)}$ (Cybermed Co., Seoul, Korea) software program for the virtual planning, five fixtures of MK III Groovy RP implants of Branemark System$^{(R)}$ (Nobel Biocare AB Co., Goteborg, Sweden) were installed in the anterior mandible between both mental foramens using In2Guide$^{(R)}$ (CyberMed Co., Seoul, Korea) mucosa-supported surgical template with Quick Guide Kit$^{(R)}$ (Osstem Implant Co., Seoul, Korea) systems. Fixture installations were completed successfully without any complications, such as mental nerve injury, bony bleedings, fenestrations and other unexpected events. Postoperative computed tomographic scans were aligned and fused to the planned implant, then angular and linear deviations were compared with the planned virtual implants. The mean angular deviation between the planned and actual implant axes was $3.42{\pm}1.336^{\circ}$. The mean distance between the planned and actual implant at the neck area was $0.544{\pm}0.290$ mm horizontally and $0.118{\pm}0.079$ mm vertically. The average distance between the planned and actual implant at the apex area was $1.166{\pm}0.566$ mm horizontally and $0.14{\pm}0.091$ mm vertically. These results could be considered more precise and accurate than previous reports, and even our recent results. The entire procedures of this case are reported and reviewed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.5
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• pp.337-342
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• 2012

The osseous or osteocutaneous free fibula flap has become the gold standard for most mandibular reconstructions because of its favorable osseous characteristics. However, disadvantages, such as the time-consuming reconstructive step, difficulty in performing the osteotomies to precisely recreate the shape of the missing segment of mandible and poor bone-to-bone contact play a role in making the surgeons look for alternative flaps. With the advent of computerized design software, which accurately plans complex 3-dimensional reconstructions, has become a process that is more efficient and precise. However, the ability to transfer the computerized plan into the surgical field with stereolithographic models and guides has been a significant development in advancing reconstruction in the maxillofacial regions. The ability to "pre-plan" the case, mirror and superimpose natural structures into diseased and deformed areas, as well as the ability to reproduce these plans with good surgical precision has decreased overall operative time, and has helped facilitate functional and esthetic reconstruction. We describe a complex case treated with this technique, showing the power and elegance of computer assisted maxillofacial reconstruction from the University of Michigan, Oral and Maxillofacial Surgery.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.3
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• pp.285-288
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• 2022

Three-dimensional (3D) modeling of the liver can be especially useful for both the surgeon and patient to understand the actual location of the tumor and planning the resection plane. Virtual reality (VR) can enhance the understanding of 3D structures and create an environment where the user can focus on contents provided. In the present study, a VR platform was developed using Unreal Engine 4 software (Epic Games, Potomac, MD, USA). Patient's liver based on magnetic resonance image was imported as a 3D model that could distinguish liver parenchyma, vascular structure, and cancer. Preoperative education videos for patients were developed. They could be viewed inside the VR platform. To evaluate the usefulness of VR education program for patients undergoing liver resection for hepatocellular carcinoma, a randomized clinical trial evaluating the knowledge and anxiety of the patient was designed. The case presented in this report was the first experience of performing the VR education program and examining the knowledge and anxiety using questionnaires. When the knowledge score increased, the anxiety score also increased after the education program. Based on findings of this pilot case study, the timing and place where the questionnaire will be answered can be modified for formal initiation of the randomized controlled study to examine the usefulness of VR in patient education.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.2.1-2.7
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• 2018

With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.