• 대한치과교정학회지
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• 제51권5호
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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.

• Journal of Oral Medicine and Pain
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• 제44권4호
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• pp.154-159
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• 2019

Purpose: The aim of this study was to assess the change in thickness of the roof of the glenoid fossa (RGF) in patients undergoing orthognathic surgery using cone-beam computed tomography (CBCT) images. Methods: This retrospective study measured the thickness of the RGF in 19 patients (10 males, 9 females) who underwent orthognathic surgery at Chosun University Dental Hospital. The thickness of the RGF was measured perpendicularly between the 'glenoid fossa line' and 'middle cranial fossa line' on parasagittal and paracoronal reconstructions. Results: The mean RGF thickness increased from 0.83±0.44 mm to 0.86±0.46 mm after surgery. The average change in thickness of the RGF was 0.17±0.18 mm. The thickness of the RGF in the temporomandibular joint (TMJ) showed no significant difference by sex, and the change in thickness of the TMJ did not vary by surgical method. Conclusions: We found that the thickness of the RGF increased after orthognathic surgery, as revealed by CBCT. Further studies including larger numbers of subjects and long-term follow-up are needed to confirm the results of this study.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권1호
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• pp.63-67
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• 2022

Controversies exist regarding the need for prophylactic extraction of mandibular third molars in patients who plan to undergo orthognathic surgery. An 18-year-old male patient was diagnosed with mandibular prognathism and maxillary retrognathism with mild facial asymmetry. He had a severely damaged mandibular first molar and a horizontally impacted third molar. After extraction of the first molar, the second molar was protracted into the first molar space, and the third molar erupted into the posterior line of occlusion. The orthognathic surgery involved clockwise rotation of the maxillomandibular complex as well as angle shaving and chin border trimming. Patients who are missing or have damaged mandibular molars should be monitored for eruption of third molars to replace the missing posterior tooth regardless of the timing of orthognathic surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권2호
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• pp.127-135
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• 2009

Objectives : The titanium fixation system has been used in orthognathic surgery for fixation of bone segments usually, but the biodegradable fixation system was developed and also being used. The strongest point in the biodegradable system is that no extra operation should be needed to remove fixation materials. In spite of this merit, oral & maxillofacial surgeons hesitate to use this system in fracture or orthognathic surgery. In this study, as we got some clinical experiences, we'd like to report the result of clinical study using the biodegradable fixation system in orthognathic surgery. Patients and Methods : A total of 35 patients composed of 17 males and 18 females with 25 osteotomies in maxilla and 34 osteotomies in mandible were fixated with the biodegradable fixation system(Inion $CPS^{(R)}$). We investigated methods of stabilization, fixation time, and complications on the basis of the method as above. Results : Four 2mm thick L shaped plates with 7 holes of which 1 hole was removed were fixed in maxilla with six $2.0{\times}7mm$ screws. Three $2.5{\times}16{\sim}18mm$ screws were used to fix superior ramus area and one mandibular angle area in mandible. It took about 27.4 minutes in maxilla, 25.3 minutes in mandible to perform the fixation which took longer time than the titanium system(9.5 minutes in maxilla, 8 minutes in mandible). Generally, there was no problem except 9 cases in which there were some complications. Conclusions : In most cases, the biodegradable fixation system can be used without problem in usual orthognathic surgery. But, this system is inferior to the titanium fixation one in some respects such as fixation time, size, and physical property. Some supplementations for such weak points as aforementioned should be needed for the universal use of biodegradable materials.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권3호
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• pp.178-181
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• 1993

Sixty four patients were followed-up for over 6 months following the orthognathic surgeries and were examined for the Temporo-mandibular joint dysfunction. The results are as follows: 1. Of 64 patients, 9(14.1%) had been suffered from TMD preoperatively : 4.7% in the prognathism and 46.2% in the laterognathism. 2. Following the orthognathic surgeries, 7 of 64 patients(10.9%) complained TMD, and 55.6% of the TMD patients resulted in significant improvement. 3. By the type of deformities, laterognathism with TMD could be expected to be improved in 30.8%, while 7.7% in the prognathism. 4. Non-rigid fixation resulted in higher incidence of TMD than the Rigid fixation after the SSRO ; 4 of 15(26.5%) and 2 of 25(8.0%) respectively.

• Journal of International Society for Simulation Surgery
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• 제1권1호
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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 the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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• pp.407-413
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• 2000

To evaluate the stability after orthognathic surgery in cleft lip and palate patients using rigid fixation, 20 patients underwent primary repair in childhood and later developed a jaw deformity and malocclusion that required orthognathic surgery were reviewed. Two groups, one of 10 patients performed Le Fort I osteotomy with sagittal split ramus osteotomy and one of 10 patients with sagittal split ramus osteotomy of the mandible, were evaluated. Each group had unilateral cleft only and all alveolar cleft sites had been grafted with autogeneous bone before the orthognathic surgery. The amount of surgical movement and relapse were compared in both horizontal and vertical dimensions. Two-jaw surgery group was more stable than mandibular surgery only group in mandibular position (p< 0.05). Statistically significant relapse was observed in mandibular skeletal point in mandibular surgery group (p<0.05). There was no statistically significant relapse in the skeletal point of two-jaw surgery group. However, the correlation between the horizontal surgical movement and relapse was detected (r = 0.88). This correlation indicates the need of overcorrection. The presence of scar tissues and relatively deficient maxillary bone could be attributed to this close relation between the surgical change and relapse.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권4호
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• pp.260-266
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• 2012

Purpose: The purpose of this study is to identify the changes of a physiologic nature and the sedative parameters associated with dexmedetomidine and pethidine, in patients undergoing plate and screw removal surgery, after orthognathic surgery. Methods: Twenty-three patients were sedated with dexmedetomidine and pethidine during plate and screw removal, after orthognathic surgery. An initial loading dose of dexmedetomidine ($1.0{\mu}g/kg$ infused over 10 minutes) was followed by a maintenance dose ($1.0{\mu}g/kg/hr$). Systolic blood pressure, diastolic blood pressure, mean arterial pressure, oxygen saturation, and heart rate were monitored. Perioperative amnesia and anxiety were recorded. Results: Significant changes were found in the blood pressure and heart rate (Freidman test, P<0.05), but not in oxygen saturation (Freidman test, P>0.05). Amnesia during local injection was observed in eight patients (34.8%). Compared with the preoperative anxiety score, the intraoperative anxiety score was decreased. Conclusion: In this study, we found cardiovascular and respiratory stability in intravenous sedation using dexmedetomidine with pethidine, in plate and screw removal, after orthognathic surgery. Furthemore, intravenous sedation using dexmedetomidine with pethidine shows adequate analgesic and sedative effects.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권2호
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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.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권4호
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• pp.351-358
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• 2010

A 31-year-old woman with hemifacial microsomia presented to the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. The patient was previously treated with distraction osteogenesis device to elongate right maxilla and mandibular ramus. But, the result was not satisfactory, to correct residual facial asymmetry due to hemifacial microsomia we planned costochondral graft for reconstruction of ramus and condyle, Le Fort I osteotomy and sagittal split ramus osteotomy for facial asymmetry. The right mandibular condyle and ramus was reconstructed with right eleventh costochondral graft via submandibular approach. Using costochondral graft and orthognathic surgery the facial asymmetry in hemifacial microsomia patient was corrected. 1-stage treatment consists of costochondral graft and orthognathic surgery can achieve function and esthetics at the same time, is timesaving to both patient and surgeon.