• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권2호
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• pp.130-136
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• 2005

Bone grafts are widely used in the reconstruction of osseous defects in the oral and maxillofacial region. Autogenous bone grafts are considered the gold standard in grafting of the oral and maxillofacial region, because of its osteoconductive and osteoinductive properties. Mandibular symphysis & ascending ramus bone graft have been used more frequently because of easy surgical access, reduced operative time, and following minimal morbidity. However, even though the frequent use of the anterior part of ascending ramus and the different regions of mandible, rare of the reports provide information about the quantity of bone available in this donor site. So this study was taken to evaluate & quantify the amount of bone graft material in the anterior ascending ramus regions. This study was made on 36 samples of CT image. In 3D volume image, imaginary osteotomy & segmentation were done and the dimensions and volume of the bone grafts were measured and evaluated. the average volume of the graft materials obtained from the ascending ramus was $3656.83{\pm}108.19mm^3$, and the average dimensions of graft materials were $(33.68{\pm}0.48){\times}(34.92{\pm}0.51){\times}(15.96{\pm}0.27){\times}(9.05{\pm}0.27)mm$.

• Imaging Science in Dentistry
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• 제49권4호
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• pp.257-263
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• 2019

Purpose: This study was performed to evaluate the dimensional accuracy of digital dental models constructed from cone-beam computed tomographic (CBCT) scans of polyvinyl siloxane (PVS) impressions and cast scan models. Materials and Methods: A pair of PVS impressions was obtained from 20 subjects and scanned using CBCT (resolution, 0.1 mm). A cast scan model was constructed by scanning the gypsum model using a model scanner. After reconstruction of the digital models, the mesio-distal width of each tooth, inter-canine width, and inter-molar width were measured, and the Bolton ratios were calculated and compared. The 2 models were superimposed and the difference between the models was measured using 3-dimensional analysis. Results: The range of mean error between the cast scan model and the CBCT scan model was -0.15 mm to 0.13 mm in the mesio-distal width of the teeth and 0.03 mm to 0.42 mm in the width analysis. The differences in the Bolton ratios between the cast scan models and CBCT scan models were 0.87 (anterior ratio) and 0.72 (overall ratio), with no significant difference (P>0.05). The mean maxillary and mandibular difference when the cast scan model and the CBCT scan model were superimposed was 53 ㎛. Conclusion: There was no statistically significant difference in most of the measurements. The maximum tooth size difference was 0.15mm, and the average difference in model overlap was 53 ㎛. Digital models produced by scanning impressions at a high resolution using CBCT can be used in clinical practice.

• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.621-628
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• 2008

Purpose: Osteopontin is one of the major non-collagenous protein of hard tissue. Use of peptide domain of biologically active protein has some advantages. The objective of this experimental study is evaluation of periodontal regenerative potency of synthetic peptide gel which containing collagen binding domain of osteopontin in the degree III periodontal defect of beagle dogs. Material and Methods: Experimental degree III furcation defect was made in the mandibular third and fourth premolar of beagles. Regenerative material was applied during flap operation. 8 weeks after regenerative surgery, all animals were sacrificed and histomorphometric measurement was performed to calculate the linear percentage of the new cementum formation and the volume percentage of new bone formation. Result: The linear percent of new cementum formation was 41.6% at control group and 67.1% at test group and there was statistically significant difference. The volume percent of new bone formation was 52.1% at control group and 58.9% at test group. Conclusion: As the results of present experiment, synthetic peptide gel containing collagen binding domain of osteopontin significantly increase new bone and cementum formation in the degree III furcation defect of canine mandible.

• 대한치과보철학회지
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• 제32권3호
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• pp.431-443
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• 1994

As the dental arch is the curve connecting the cusp tip of tooth, the dental arch form, composing of the occlusion, is one the important factors of occlusal reconstruction. Many studies about the horizontal dental arch form have been reported, but until now, it is unclear to infer the position of the teeth in dental arch form, to evaluate the effect of the horizontal dental arch form on chewing movement. The purpose of this study is to make objective criteria to infer the position of the teeth in dental arch. In this study, 100 subjects with individdual normal occlusion were evaluated. By multiple regression analysis on the basis of the relation of the canine and the first molar, the positions of teeth in dental arch were inferred. According to buccolingual relationship of maxillary to mandibular posterior teeth, the dental arch forms were classified into five groups, i, e. the normal group, the group which the maxillary second molar positions buccal side, the group which the maxillary premolars position buccal side, the group which the maxillary premolar position lingual side. From the results, objective criterial to infer the positons of the first premolar, the second premolar, the second molar in dental arch were made.

• Journal of Korean Dental Science
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• 제7권1호
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• pp.38-42
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• 2014

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is defined as exposed necrotic bone without evidence of healing for at least 8 weeks in the maxillofacial area in a patient with history of bisphosphonate use. Obtaining complete coverage of the hard tissue by soft tissue in BRONJ patients is especially important. Therefore, managing the mucosa is one of the key factors in a successful outcome, but this is especially hard to achieve in BRONJ patients. Various applications of buccal fat pad in oral reconstruction-including the closure of surgical defects following tumor excision, repair of surgical defects following the excision of leukoplakia and submucous fibrosis, closure of primary and secondary palatal clefts, coverage of maxillary and mandibular bone grafts, and lining of sinus surface of maxillary sinus bone graft in sinus lift procedures for maxillary augmentation-have been studied. Eliminating all potential sites of infection and post-operative infection control is crucial in BRONJ. We present a case using the buccal fat pad pedicle for a stage 3 BRONJ defect. Uneventful total epithelialization of the buccal fat pad regardless of size was noted. In summary, the buccal fat pad has versatile application and various recipient sites for surgical utilization. It is an easy technique, with promising overall success rates. With careful selection and handling, buccal fat graft can resolve problems with soft tissue coverage in stage 2 or 3 BRONJ patients.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제11권2호
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• pp.40-46
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• 1989

출생 전${\cdot}$후 악관절의 외상 또는 감염은 과두 성장을 방해하며 편측으로 발생하는 경우 하악골의 비대칭 성장을 초래하여 심한 안모 변형과 부정교합을 유발하거나 악관절 유착의 주된 원인이 된다. 역사적으로 관절 유착은 과두절단술에서부터 연골이식, 진피이식, 금속과두 이식, 관절 성형술, 관절과 이식물 삽입에 이르기까지 매우 다양한 방법에 의해 치료되어 왔으며 하악운동이 보장되고 정상적인 기능을 회복하는데는 어떤 술식이라도 만족스런 결과를 가져다줄 수 있다. 이에 저자는 편측성 악관절 강직증 및 비대칭 안모를 가진 환자에서 과두절제술 후 금속 과두이식을 이용한 악관절 재건과 하악 골체부 절단술 및 C-sliding 절단술, 하악지 수직 골절단술, Medpor를 이용한 증식술로 개구기능과 비대칭 안모를 개선하여 비교적 만족할 만한 결과를 얻었기에 그 치험례를 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.3.1-3.7
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• 2015

Hemifacial microsomia (HFM) is the most common craniofacial anomaly after cleft lip and cleft palate; this deformity primarily involves the facial skeleton and ear, with either underdevelopment or absence of both components. In patients with HFM, the management of the asymmetries requires a series of treatment phases that focus on their interception and correction, such as distraction osteogenesis or functional appliance treatment during growth and presurgical orthodontic treatment followed by mandibular and maxillary surgery. Satisfactory results were obtained in a 9-year-old girl with HFM who was treated with distraction osteogenesis. At the age of 19, genioplasty and mandible body augmentation with a porous polyethylene implant (PPE, $Medpor^{(R)}$, Porex) was sequentially performed for the functional and esthetic reconstruction of the face. We report a case of HFM with a review of the literature.

• Journal of Oral Medicine and Pain
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• 제24권1호
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• pp.69-80
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• 1999

OBJECTIVES: This study was designed to measure the minimal cross-sectional areas and volumes of the pharynx in snoring patients and normal subjects and to see if there is an increase in the minimal cross-sectional areas and volumes of the pharynx with advancement of the mandible. METHODS: The pharyngeal computed tomography and 3-dimensional reconstruction were used to measure the cross-sectional areas and volumes of the nasopharynx, oropharynx, and hypopharynx with the jaw in normal position and in protrusive position in 7 patients with snoring and 7 control subjects while they were awake. RESULTS: The oropharynx was revealed to have the most narrow site in the pharynx and there was a tendency for the snorers to have a smaller nasopharyngeal and oropharyngeal cross-sectional area than normal subjects but not statistically significant. There were no significant differences in the volumes of the nasopharynx and oropharynx between the two groups. With advancement of the jaw the minimal cross-sectional area of oropharynx was significantly increased, and the volume was also increased but not significantly. The minimal cross-sectional areas and volumes of nasopharynx as well as hypopharynx were not significantly influenced by the advancement of the mandible. CONCLUSIONS: There was a tendency for snorers to have a smaller oropharynx than normal subjects and the oropharyngeal lumen was increased with the advancement of the mandible in both snorers and normal subjects.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.378-385
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• 2004

The purpose of this study was to compare the effects of preparation with GT files and profiles .04 in shaping of root canals and reconstruct the three-dimensional root canal system using micro computed tomography 40 canals of the extracted human mandibular molars were used, and randomly distributed into two experimental groups. In group 1. canals were prepared by GT files. In group 2, Profiles .04. were used. Apical preparation size was #30. For each tooth pre and post operative cross-sectional images were obtained by the micro CT at 50 micron intervals. Pre and post operative cross-sectional images of 1, 2, 3, 5, and 8mm from the apex were compared. For each section. canal area and centering ratio were determined. For each tooth pre- and post-operative root canal volume from the furcation to the apex of the roots was calculated by three-dimensional image software. Following results were obtained: 1. At 8mm from the apex, area of dentin removed by GT rotary file was significantly larger than that by Profile .04. And at the other levels there was not a significant difference. 2. There was a trend for GT rotary file to remain more centered in the canals than Profile .04 at all levels. But at 3mm level. there was a statistically significant difference. 3. In root canal volume increments after instrumentation, there was no significant difference between two groups.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권1호
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• pp.109-113
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• 2000

Synovial chondromatosis is an uncommon disease of cartilage transformation of synovial membrane with formation of loose bodies within the joint space. The knee and elbow are the most commonly involved sites and involvement of temporomandibular joint is very rare. Symtoms include swelling, pain, stiffness of the jaw, and inability to close the jaw. A case involving the temporomandibular joint(TMJ) is presented. A 28-year-old women had experienced pain of the left TMJ area and limitation of mouth opening. Radiographs of the left TMJ revealed calcified mass surrounding over the mandibular condyle and under the glenoid fossa. Treatment consisted of removal of calcified mass, reshaping of affected condyle and reconstruction with a auricular cartilage. After surgery, the patient's range of motion improved although deviation to the affected side. Until present after surgery there have been no recurrence of symtoms. We think that findings of this patitent agree with those of synovial synchondrmatosis in many aspects.