• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권3호
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• pp.233-242
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• 1997

Recently the goal of orthognathic surgery has been focused on esthetic improvement of the patients. Also early corrective surgery was favorable selected by most of the oral and maxillofacial surgeons. We should consider the etiologic factor of the patient's dentofacial deformities when treatment is planned, because this is the major factor in estimating the predictability or stability of result. The more researches were carried on the etiologic factors of the dentofacical deformities, The more possibility of the early surgical correction will be increased. The authors analyzed about etiologic factors and epidemiologic studies of the forth patients who had received the orthognathic surgery. The analyzed results were as follows: 1. The predilection ration between male and female was 17:23, and 32 patients (80%) of 40 patients were aged twenties. 2. 26patients(65%) complained estetic problems as well as functional problems. 10 patients(25%) complained only esthetic problems, and 4 of 40 patients complained only functional problems. 3. Mandibular prognathism was found to be done most frequently(25, 39%). Facial asymmetry (13, 20%) and angle hypertrophy were found to be next in sequence. 4. Sagittal split ramus ostetomy was done most frequently(27, 35%). Lefort I osteotomy(13, 17%), angle reduction (12,16%), and genioplasty(11, 15%) were done also. 5. The number of the cases due to nonspecific etiologic factor was 22(55%), that of cases due to inhertied tendency was 12(30%), that of cases due to congenital anomaly was 3(7.5%), and that of cases due to trauma was 3(7.5%). 6. The number of patients who got only maxilliary surgery was 2(5%), that of patients who got only mandibular surgery was 23(57.5%), and that of patients who got simultaneous two jaw surgery was 15(37.5%).

• 대한치과교정학회지
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• 제50권3호
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• pp.206-215
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• 2020

Osteochondroma is a common benign tumor of bones, but it is rare in the mandibular condyle. With its outgrowth it manifests clinically as deviation of the mandible limitation of mouth opening, and facial asymmetry. After the tumor is diagnosed on the basis of clinical symptoms and radiographic examination including cone-beam computed tomography (CBCT) analysis, an appropriate surgery and treatment plan should be formulated. Herein, we present the case of a 44-year-old female patient who visited our dental hospital because her chin point had been deviating to the left side slowly but progressively over the last 3 years and she had difficulty masticating. Based on CBCT, she was diagnosed with skeletal Class III malocclusion accompanied by osteochondroma of the right mandibular condyle. Maxillary occlusal cant with the right side down was observed, but it was confirmed to be an extrusion of the molars associated with dental compensation. Therefore, after intrusion of the right molars with the use of temporary anchorage devices, sagittal split ramus osteotomy was used to remove the tumor and perform orthognathic surgery simultaneously. During 6 months after the surgery, continuous bone resorption and remodeling were observed in the condyle of the affected side, which led to a change in occlusion. During the postoperative orthodontic treatment, intrusive force and buccal torque were applied to the molars on the affected side, and a proper buccal overjet was created. After 18 months, CBCT revealed that the rate of bone absorption was continuously reduced, bone corticalization appeared, and good occlusion and a satisfying facial profile were achieved.

• Imaging Science in Dentistry
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• 제32권4호
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• pp.201-206
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• 2002

Purpose : To evaluate the radiographic change of operation sites after orthognathic surgery using the digital image processing and fractal analysis. Materials and Methods : A series of panoramic radiographs of thirty-five randomly selected patients who had undergone mandibular orthognathic surgery (bilateral sagittal split ramus osteotomy) without clinical complication for osseous healing, were taken. The panoramic radiographs of each selected patient were taken at pre-operation (stage 0), 1 or 2 days after operation (stage 1), 1 month after operation (stage 2), 6 months after operation (stage 3), and 12 months after operation (stage 4). The radiographs were digitized at 600 dpi, 8 bit, and 256 gray levels. The region of interest, centered on the bony gap area of the operation site, was selected and the fractal dimension was calculated by using the tile-counting method. The mean values and standard deviations of fractal dimension for each stage were calculated and the differences among stage 0, 1, 2, 3, and 4 were evaluated through repeated measures of the ANOVA and paired t-test. Results : The mean values and standard deviations of the fractal dimensions obtained from stage 0, 1, 2, 3, and 4 were 1.658±0.048, 1.580±0.050, 1.607±0.046, 1.624±0.049, and 1.641 ±0.061, respectively. The fractal dimensions from stage 1 to stage 4 were shown to have a tendency to increase (p < 0.05). Conclusion: The tendency of the fractal dimesion to increase relative to healing time may be a useful means of evaluating post-operative bony healing of the osteotomy site.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제14권1_2호
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• pp.135-142
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• 1992

This study was performed to define the anatomical position of the mandibular canal and the findings during the sagittal split ramus osteotomy of the mandible. The mandibles of 20 adult Korean were used. The dimension of mandibular canal from the mandibular foramen to the 1st molar was measured at 4 specific coronal-sectional location by CT scan. The results were as follows ; 1. The distance from the mandibular canal to the medial aspect of the buccal cortical plate was greatest($4.5{\pm}1.1mm$) at 2nd molar area and was not significantly greater than at any other section. 2. Buccal cortex was thickest($3.8{\pm}0.9mm$) at 2nd molar and thinnest ($2.5{\pm}0.3mm$) mandibular foramen um 3. The distance from the mandibular canal to the medial aspect of the lingual cortical plate was not significant at any sections. 4. The distance from the mandible canal to the inferior border of mandible was greatest at the mandibular foramen($20.7{\pm}3.9mm$). The canal was located more closely to the inferior border at 1st, 2nd molar area 5. The diameter of the mandibular canal was between $2.5{\pm}0.3mm$ and $2.8{\pm}0.6mm$. 6. The total mandibular thickness was greatest($21.1{\pm}2.6mm$) at 2nd molar area and narrowest($17.2{\pm}3.2mm$) at mandibular foramen area.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권6호
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• pp.584-588
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• 2008

Facial asymmetry is particularly associated with mandible among other facial bones and it could be either congenital or acquired. Congenital factors are related to Treacher Collin syndrome, Pierre Robin syndrome, hemifacial microsomia and other various syndromes. Acquired factors are such as damaged or diseased growing condyles, hormonal disorder, oral mal-habit, muscular force, tumor, infection and so on. Diagnosis and treatment of facial asymmetry are complicated due to differences in sizes and positions of mandibles. The aspects of facial asymmetry is various and complicated upon each individual. Depending on causes of the facial asymmetry, there also are morphological differences. For such reasons, precise anatomical analysis and diagnosis of the facial asymmetry are essential before any surgical procedure followed by the appropriate treatment plan. This case is regarding a 21-year old patient diagnosed as the facial asymmetry due to an infantile maxillofacial surgery. Employing various morphological evaluations, potential problems during the procedure are predicted beforehand. This case reports a favorable result of sagittal split ramus osteotomy performing the oblique vertical bone cutting in posterior-superior of the mandibular second molar.

• 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.

• 대한치과교정학회지
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• 제43권1호
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• pp.42-52
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• 2013

The aim of this paper was to propose a new method of bimaxillary orthognathic surgery planning and model surgery based on the concept of 6 degrees of freedom (DOF). A 22-year-old man with Class III malocclusion was referred to our clinic with complaints of facial deformity and chewing difficulty. To correct a prognathic mandible, facial asymmetry, flat occlusal plane angle, labioversion of the maxillary central incisors, and concavity of the facial profile, bimaxillary orthognathic surgery was planned. After preoperative orthodontic treatment, surgical planning based on the concept of 6 DOF was performed on a surgical treatment objective drawing, and a Jeon's model surgery chart (JMSC) was prepared. Model surgery was performed with Jeon's orthognathic surgery simulator (JOSS) using the JMSC, and an interim wafer was fabricated. Le Fort I osteotomy, bilateral sagittal split ramus osteotomy, and malar augmentation were performed. The patient received lateral cephalometric and posteroanterior cephalometric analysis in postretention for 1 year. The follow-up results were determined to be satisfactory, and skeletal relapse did not occur after 1.5 years of surgery. When maxillary and mandibular models are considered as rigid bodies, and their state of motion is described in a quantitative manner based on 6 DOF, sharing of exact information on locational movement in 3-dimensional space is possible. The use of JMSC and JOSS will actualize accurate communication and performance of model surgery among clinicians based on objective measurements.

• Journal of Yeungnam Medical Science
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• 제12권2호
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• pp.393-399
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• 1995

심한 하악 후퇴증은 교정치료만으로 성공적인 결과를 얻을 수 없으며 골절단술, 이부성형술등 외과적 교정이 고려되어야 한다. 설골상근의 장력에 의한 회귀현상을 최소화하기 위해 수술시 하악 체부를 전방회전시킴과 동시에 가능한 전방으로 overcorrection한다. 저자등은 구미인에 비해 발생빈도가 적은 하악 후퇴증을 주소로 내원한 환자를 양측성 하악골 시상절단술과 이부 성형술을 통하여 만족할만한 안모개선 및 교합관계 개선을 이루었기에 이에 보고하는 바이다.

• 대한치과교정학회지
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• 제29권4호
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• pp.457-466
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• 1999

하악 후퇴술 후의 골격성 재발과 치열 변화는 악간고정(intermaxillary fixation, IMF)제거 후 뿐만 아니라 악간고정기간 중에도 일어난다고 보고되고 있다. 악간고정기간 중에 일어나는 골격성 재발에 따른 골편간 견고한 융합의 방해, 보상성 치아이동, 전치부 개방교합 등과 같은 여러 가지 부작용은 술후 교정치료에 많은 영향을 미칠 수 있으므로 임상적으로 중요한 의미를 갖는다. 본 연구는 악간고정기간 중에 일어나는 골격성 재발과 치열의 변화를 알아보고자 시행하였으며, 하악전돌증의 치료를 위해서 양측성 하악지 시상분할골절단술(bilateral sagittal split ramus osteotomy, BSSRO)과 강선고정 (wire fixation), 악간고정을 시행한 28명을 대상으로 하였다. 본 연구에서는 측모 두부 방사선 사진을 통하여 수술에 의한 골편들의 이동량과 방향, 악간고정기간 중의 골격성 재발과 치열 변화의 양과 방향을 측정하였다. 또한 수술에 의한 골편들의 이동과 골격성 재발과의 상관관계, 골격성 재발과 치열 변화간의 상관관계를 평가하였다. 본 연구를 통하여 다음과 같은 결론을 얻었다. 1. 수술에 의한 골편의 이동방향은 원심골편은 후상방으로, 근심골편은 시계방향으로 회전하였다. 2. 악간고정기간 중에 원심골편의 전방부는 후방 변위, 후방부는 상방 변위하였으며 근심골편은 상방 변위와 함께 근심골편의 gonion(p-Go)부위는 전방 변위를 하였다. 악간고정기간중에 근심골편의 gonion(p-Go)의 전방 변위는 수술에 의한 근심골편의 gonion (p-Go)의 후방으로의 이동량과 유의한 상관관계를 보였다. 즉, 수술에 의한 근심골편의 gonion(p-Go)의 후방으로의 이동이 많을수록 악간고정기간 중의 근심골편의 gonion(p-Go)의 전방 변위는 증가하였다. 3. 악간고정기간 중에 수평피개, 수직피개는 변화가 없었다. 상악 전치부는 후방경사(retroclination), 하악 전치부는 후방경사, 정출이 일어났으며, 이러한 보상성 치아이동은 악간고정기간 중의 근심골편의 gonion(p-Go)의 상방 변위와 유의한 상관관계를 보였다. 즉, 악간고정기간 중의 근심골편의 gonion(p-Go)의 상방 변위가 클수록 보상성 치아 이동량도 증가하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.206-216
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• 2000

저자는 1996년 1월에서 1998년 10월까지 본원에서 하악지시상분할골절단술을 시행한 하악전돌증환자중 35명(남자15명, 여자 20명)을 무작위로 선정하여 수술전, 수술직후 및 술후 1년의 하악각변화를 분석한 결과 다음과 같은 결론을 얻었다. 1. 35명 환자의 하악각평균은 술직후에는 술전에 비해 $9.3^{\circ}$ 감소하였다가 술후 1년까지 $4.0^{\circ}$증가하여 술전에 비해 술후 1년의 하악각은 $5.3^{\circ}$감소하였다(p<0.01). 2. 35명 환자의 악교정수술전 하악각평균은 $129.4^{\circ}({\pm}6.27)$로 정상에 비해 유의있게 큰 값을 보였으며 하악지시상분할골절단술 후 1년의 하악각평균은 $124.1^{\circ}({\pm}6.33)$로 비교적 개선되었다. 3. 술전과 술후 1년 사이의 남녀의 하악각변화는 여자는 $5.4^{\circ}$감소, 남자는 $5.3^{\circ}$감소로서 남녀간에 유의한 차이는 없었다(p>0.05). 4. 35명의 하악지시상분할골절단술을 받은 환자의 술전과 술후 1년 사이의 하악각변화에서 하악각감소에 관여하는 가장 주요한 변수는 하악후퇴량이었다. 5. 35명의 하악지시상분할골절단술을 받은 환자의 술직후부터 술후 1년까지의 하악각변화에서 하악각증가에 관여하는 가장 주요한 요인은 수평회귀율이었으며 원심골편후방부의 흡수현상도 하악각증가에 관여하는 것으로 생각되었다. 결론적으로 하악전돌증 환자에 있어 하악각이 정상보다 큰 경우 하악지시상분할골절단술은 하악각개선에 효과적이었으며 하악각이 정상에 가깝고 과도한 하악후퇴량이 요구되는 경우는 Short lingual cut 방법, 부가적인 원심골편의 후방변연절제술, Obwegeser II 방법과 같은 하악우각부 형태를 유지하는 수술법을 선택함이 유리할 것으로 예상되고 술후 회귀방지책이 안정된 하악각유지에도 도움이 될 것으로 사료된다.