• The Journal of the Korean dental association
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• v.56 no.11
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• pp.622-630
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• 2018

For successful surgery-first approach, accurate prediction of skeletal and dental changes following orthognathic surgery is essential. With recent development of digital technology using computer-aided design/computer-aided manufacturing (CAD/CAM) technology, attempts to provide more predictable orthodontic/orthognathic treatment have been made through 3D virtual surgery and digital tooth setup. A clinical protocol for the surgery-first orthognathic approach using virtual surgery is proposed. A case of skeletal Class III patient with facial asymmetry treated by the surgery-first approach using digital setup and virtual surgery is presented. Advantages and limitations of applying CAD/CAM technology to orthognathic surgery are discussed.

• Journal of International Society for Simulation Surgery
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• v.2 no.2
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• pp.71-75
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• 2015

To overcome limitations of conventional diagnosis and planning for orthognathic surgery, surgeons have begun to use 3-dimensional (3D) virtual simulation to plan complex orthognathic surgery. In many literatures, it has shown that better surgical outcome achieved with 3D virtual simulation than that with conventional methods. But, there is still lack of data about accuracy of maxillary segmental surgery with 3D virtual simulation. The purpose of this paper was to report the case of maxillary segmental orthognathic surgery with 3D virtual simulation and to assess the actual surgical outcome. Though the result was clinically acceptable, discrepancy between 3D simulation and actual surgery was not superior compared with conventional method. The accuracy of 3D simulation surgery and intermediate wafer fabrication for maxillary segmental surgery needs to be improved. Advancement in 3D software program and careful surgical technique will make it more precise and reliable method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.158-166
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• 2009

The application of CT with basis on 3 dimensional-reconstruction is getting more widely practiced. With the data obtained from cone-beam computed tomography(CBCT), not only the diagnosis of the patient with skeletal abnormality but also the virtual simulation of the orthognathic surgery were performed and its application would be popular in orthodontic field. We reported a case, a 19-year old man who was diagnosed mandibular prognathism and required orthognatic surgery. In this case, the virtual orthognathic surgery was simulated and surgical wafer was fabricated by using CBCT data. That wafer was applied the actual orthognathic surgery. After preoperative orthodontic treatment, we prepared surgery as follows. : (l)Acquisition of 3D image data, (2)Reconstruction of 3-dimensional virtual model, (3)Virtual model surgery, (4)Extraction of stere-olithographic image, (5)Check-up for occlusal interference, (6)Fabrication of surgical stent by stereolithography. Bilateral sagittal split ramus osteotomy was operated and used stereolithographic surgical stent. 1 month later, we superimposed CBCT datas of virtual surgery and that of actual surgery, and then compared the result. CT data's application for othognathic surgery yielded satisfactory outcomes.

• Journal of International Society for Simulation Surgery
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• v.1 no.1
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• pp.23-26
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• 2014

The aim of this report is to evaluate accuracy using3D surgical simulationand digitally printedwafer in orthognathic surgery. 22-year-old female was diagnosed with mandibular prognathism and apertognathia based on 3D diagnosis using CT. Digital dentition images were taken by laser scanning from dental cast, and each STL images were integrated into one virtual skull using simulation software. Digitalized intermediate wafer was manufactured using CAD/CAM software and 3D printer, and used to move maxillary segment in real patient. Constructed virtual skull from 1 month postoperative CT scan was superimposedinto simulated virtual model to reveal accuracy. Almost maxillo-mandibular landmarks were placed in simulated position within 1 mm differences except right coronoid process. Thus 3D diagnosis, surgical simulation, and digitalized wafer could be useful method to orthognathic surgery in terms of accuracy.

• Journal of International Society for Simulation Surgery
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• v.3 no.2
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• pp.87-89
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• 2016

Le fort 1 osteotomy surgery is one of the most popular surgical methods for the treatment of patients with facial bone deformities. An intermediate wafer splint is used to fix the bone segment to the planned position, but there are many steps that can cause errors. To reduce these errors, we propose a method of using a surgical guide made with virtual surgical simulation.

• 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.

• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.35.1-35.7
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• 2019

Background: The purpose of this study was to measure the time of the conventional surgical planning (CSP) and virtual surgical planning (VSP) in orthognathic surgery and to compare them in terms of cost. Material and method: This is a retrospective study of the patients who underwent orthognathic surgery at the Pusan National University Dental Hospital from December 2017 to August 2018. All the patients were analyzed through both CSP and VSP, and all the surgical stents were fabricated through manual and three-dimensional (3D) printing. The predictor variables were the planning method (CSP vs. VSP) and the surgery type (group I: Le Fort I osteotomy + bilateral sagittal split osteotomy [LFI+BSSO] or group II: only bilateral sagittal split osteotomy [BSSO]), and the outcomes were the time and cost. The results were analyzed using the paired t test. Results: Thirty patients (12 females, 18 males) met the inclusion criteria, and 17 patients were excluded from the study due to missing or incomplete data. There were 20 group I patients (LFI+BSSO regardless of genioplasty) and 10 group II patients (BSSO regardless of genioplasty). The average time of CSP for group I was 385 ± 7.8 min, and that for group II was 195 ± 8.33 min. The time reduction rate of VSP compared with CSP was 62.8% in group I and 41.5% in group II. On the other hand, there was no statistically significant cost reduction. Conclusions: The time investment in VSP in this study was significantly smaller than that in CSP, and the difference was greater in group I than in group II.

• 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.

• The korean journal of orthodontics
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• v.50 no.5
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• pp.293-303
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• 2020

Objective: To investigate the three-dimensional (3D) surgical accuracy between virtually planned and actual surgical movements (SM) of the maxilla in two-jaw orthognathic surgery. Methods: The sample consisted of 15 skeletal Class III patients who underwent two-jaw orthognathic surgery performed by a single surgeon using a virtual surgical simulation (VSS) software. The 3D cone-beam computed tomography (CBCT) images were obtained before (T0) and after surgery (T1). After merging the dental cast image onto the T0 CBCT image, VSS was performed. SM were classified into midline correction (anterior and posterior), advancement, setback, anterior elongation, and impaction (total and posterior). The landmarks were the midpoint between the central incisors, the mesiobuccal cusp tip (MBCT) of both first molars, and the midpoint of the two MBCTs. The amount and direction of SM by VSS and actual surgery were measured using 3D coordinates of the landmarks. Discrepancies less than 1 mm between VSS and T1 landmarks indicated a precise outcome. The surgical achievement percentage (SAP, [amount of movement in actual surgery/amount of movement in VSS] × 100) (%) and precision percentage (PP, [number of patients with precise outcome/number of total patients] × 100) (%) were compared among SM types using Fisher's exact and Kruskal-Wallis tests. Results: Overall mean discrepancy between VSS and actual surgery, SAP, and PP were 0.13 mm, 89.9%, and 68.3%, respectively. There was no significant difference in the SAP and PP values among the seven SM types (all p > 0.05). Conclusions: VSS could be considered as an effective tool for increasing surgical accuracy.