• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권2호
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• pp.100-105
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• 2017

Objectives: Localization of the mandibular canal (MC) and measurement of the height and width of the available alveolar bone at the proposed implant site in the posterior segment of the mandible using cone-beam computed tomography (CBCT) in patients with a single missing tooth. Materials and Methods: A cross-sectional study was performed where CBCT scans of the patients with a single missing tooth in the posterior segment of the mandible-premolar, I (1st) molar, and II (2nd) molar were used. The scans were assessed using OnDemand3D software (version 1.0; CyberMed Inc., Seoul, Korea) for localization of the MC asnd remaining alveolar bone both vertically (from the superior position of the MC to the crest of the alveolar ridge) and horizontally (buccolingual, 3 mm below the crest of the alveolar ridge). The findings were statistically analyzed using independent t-test. Results: A total of 120 mandibular sites (40 sites for each of the three missing premolar, I molar, and II molar) from 91 CBCT scans were analyzed. The average heights (from the alveolar crest to the superior margin of the MC) at the premolar, I molar, and II molar areas were $15.19{\pm}2.12mm$, $14.53{\pm}2.34mm$, and $14.21{\pm}2.23mm$, respectively. The average widths, measured 3 mm below the crest of the alveolar ridge, at the premolar, I molar, and II molar areas were $6.22{\pm}1.96mm$, $6.51{\pm}1.75mm$, and $7.60{\pm}2.08mm$, respectively. There was no statistically significant difference between males and females regarding the vertical and horizontal measurements of the alveolar ridges. Conclusion: In the study, the measurements were averaged separately for each of the single missing teeth (premolar, I molar, or II molar), giving more accurate information for dental implant placement.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권1호
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• pp.104-109
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• 1991

외상이나 감염 또는 종양의 적출에 의해 발생한 하악골 결손부는 심미적, 기능적으로 많은 문제를 야기한다. Sykoff가 1900년에 자가골 이식으로 하악골 결손부를 수복한 이후 현재까지 많은 이식물과 이식 방법이 이용되어져 왔으며 특히 늑연골은 1920년에 Gillies에 의해서 TMJ 수복에 처음 사용된 이후 성장기 아동의 과두결손부 수복에 많이 이용되고 있다. 또한 자가장골은 안면부의 수복에 보편적으로 이용되고 있는 공급부위이며 특히 많은 양의 망상골이 필요한 경우에는 후방 접근법을 이용함으로서 충분한 양의 골을 얻을 수 있다. 수복의 시기는 환자마다 차이가 있어서 나이, 과거력, 초기질별의 상태, 성장발육정도 및 심미적, 정신적인 면을 고려하여야 하며 악성종양의 제거시에는 재발여부와 방사선 치료 등을 고려하여 적절한 시기를 선택하여야 하나, 일반적으로 술후 약 1-2년 후에 시행할 수 있다. 본원에서는 하악골 골육종으로 진단된 15세 남자 환자에서 과두를 포함하는 좌측 하악골 절단술후 임시로 레진수복물을 장착한뒤 약 20개월간의 주기적인 검진결과 재발의 기미가 없어 늑연골과 장골의 복합이식을 통하여 심미적, 기능적으로 양호한 결과를 얻었기에 그 증례를 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권1호
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• pp.110-116
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• 1991

하악골 골절시 감염으로 인한 합병증에는 비유합, 부정유합, 감염에 의한 골수염, 치아 및 지지골 상실, 국소부위로부터 인접부위로 감염확장 등이 있다. 그 원인으로는 크게 국소요인과 전신요인으로 분류되는데 국소요인으로는 부적절한 고정과 수복, 감염 및 개조된 혈액공급을 들 수 있고 전신 요인으로는 부적절한 고정과 수복, 감염 및 개조된 혈액 공급을 들 수 있는 전신요인으로는 환자의 나이 및 대상장애 질환이나 primary bone disease, 영양결핍을 들 수 있다. 악골골절과 관련된 골수염은 조기에 적절한 고정 및 치료, 항생제 요법, 골절선상의 치아에 대한 치료, 전신적 저항성을 항진 시킴으로서 예방할 수 있다. 본 저자들은 하악골 골절수 이차감염으로 인한 골수염에서 골 이식의 일반적인 원칙인 감염이 없는 부위가 아닌 염증이 존재한 부위에 유리장골 이식술과 고압산소 요법을 병행하여 양호한 결과를 얻었기에 이에 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.32.1-32.8
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• 2018

Background: The free vascularized fibula flap presents many advantages such as sufficient length of the bony segment, good vascularization, better quality of the bone, and a long vascular pedicle, but it is also associated with some disadvantages with regard to prosthetic rehabilitation because of its limited height. Improvement in bone height is necessary for ideal dental implant treatment of reconstructed mandibles. Case presentation: For two squamous cell carcinoma patients, mandibular bone reconstruction was performed secondarily with the peroneal flap after tumor resection. Since the bone height was insufficient at the time of implant treatment, occlusion reconstruction by dental implant was performed after vertical distraction osteogenesis. Conclusions: Vertical distraction osteogenesis is a suitable treatment option for alveolar ridge deficiency resulting from fibula transplantation for mandibular reconstruction following tumor surgery.

• 대한치과보철학회지
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• 제33권3호
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• pp.517-538
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• 1995

Dental implantation is a method restoring missing teeth, especially in the case of severely resorbed edentulous patient. But the direct contact between bone and implant surface, induces stress concentration to the bone and eventually becomes a cause. The purpose of this study was to compare the stress distribution patterns between following two cylindrical implant models. One group has implant apex located in the inferior cortical bone and the other in the cancellous bone. Anterior edentulous mandible was modeled with two dimensional 953,878 nodes, 995,918 elements and compared the deflection and stress distribution under the 70 N,4 load cases for 26 models having variant mandibular height and length. The result were as follows; 1. The stress concentration was more affected by the height of the mandible than implant length. 2. Bicortication mitigates the stress of upper cortical and cancellous bone area at the same height of the mandible 3. Perforation of the inferior mandibular cortex significant stress concentration. 4. Stud type porstheses induced less stress concentration to the cortical and cancellous bone than bar type prostheses. 5. Stress of implant apex for stud type was larger than that of bar type.

• Imaging Science in Dentistry
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• 제34권2호
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• pp.81-89
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• 2004

Purpose: To investigate the histopathological changes in the temporomandibular joint in streptozotocin-induced diabetic rat following irradiation. Materials and Methods : Sprague-Dawley rats weighing about 250 gm were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control group were injected with citrate buffer only. After 5 days, the head and neck region of the rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the temporomandibular joint were sectioned and observed using a histopathological method. Results : In the diabetic group, severe bone resorption in the mandibular condyle was observed throughout the period of experiment. Necrosis of bone marrow and trabeculae was observed at 28 days after diabetic state. Atrophy and fibrosis in the retrodisca] tissue was gradually progressed during the time of the experiment. In the diabetic-irradiated group, severe bone resorption in the mandibular condyle was observed during the early experimental phases, but regeneration of bone marrow was initiated at ]4 days after diabetic state and irradiation. A]so, calcification of abnormal trabeculae was observed at 28 days after diabetic state and irradiation. The retrodisca] tissue was degenerated in the early experimental phases, but it had been gradually regenerated during the experimental time. Conclusion: This experiment suggests that bone resorption and degeneration in the mandibular condyle are caused by the induction of diabetes, and abnormal bone formation is induced after irradiation in diabetic state.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.27-34
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• 2006

After orthognathic surgery in skeletal class III patients, the hyoid bone position and the upper airway dimension could be changed due to mandibular setback. There has been many studies about airway dimension of the patients with skeletal class II malocclusion or obstructive sleep apnea. but not with skeletal class III. The purpose of this study was to examine the change of position of the hyoid bone and the consequent change of airway space as the result of retrusion of mandible after orthognathic surgery in skeletal Cl III malocclusion patients. It is also to apply this results in predicting, diagnosing and treating the subsequent obstructive sleep apnea. Forty patients who were diagnosed as skeletal Cl III maloccusion, received orthoganthic surgery of both jaws including mandibular setback, and were followed up post-operatively for more than 6 months were selected. There were 10 male patients 30 female patients. The preoperative and postoperative lateral cephalograms were traced and the distances and angles were measured. The nasopharyngeal space increased postoperatively while the oropharyngeal space decreased. Except for the change of oroparyngeal space, the changes in male patients were greater than female patients. The hyoid bone moved in the posterior-inferior direction, and the change was greater in males than in females. If the postoperative mandibular setback is great, then a significant decrease of airway space and posterior and inferior movement of the hyoid bone were observed. This can result in symptoms related to obstructive sleep apnea. This result should be considered in the diagnosis and treatment planning of orthognathic surgery patients.

• Imaging Science in Dentistry
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• 제43권4호
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• pp.235-243
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• 2013

Purpose: This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. Materials and Methods: One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. Results: There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, "With CCAP" and "Without CCAP", there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. Conclusion: This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

• 구강회복응용과학지
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• 제30권2호
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• pp.184-191
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• 2014

하악 구치부에 있어서 치조제 결손은 임플란트 치과학에 있어서 큰 장애물이라 할 수 있다. 이러한 치조제를 재건하는데 있어서 여러 가지 술식이 활용되고 있다. 술식들의 선택 및 필요성은 현저한 질병의 이환률과 관련이 있으며, 2차적인 수술 부위를 요구하는 경우도 있다. 골 유도 재생술(GBR, guided bone generation)의 발전은 결손이 존재하는 치조제의 이환률을 낮추며, 2차적인 수술 부위를 요구하지 않는 경우로 볼 수 있다. 본 증례에서는 심하게 결손된 하악 치조골에 자가골을 제외한 동종골, 이종골, 합성골 입자형 골이식재를 조합하여 골 유도 재생술(GBR)을 진행한 후에 임플란트를 성공적으로 식립을 하였다. 두 증례에서 양호한 식립을 보였음에 보고하는 바이다.

• 대한치과교정학회지
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• 제52권5호
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• pp.313-323
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• 2022

Objective: This study aimed to estimate the clinical effects of different types of bone-anchored maxillary protraction devices by using a network meta-analysis. Methods: We searched seven databases for randomized and controlled clinical trials that compared bone-anchored maxillary protraction with tooth-anchored maxillary protraction interventions or untreated groups up to May 2021. After literature selection, data extraction, and quality assessment, we calculated the mean differences, 95% confidence intervals, and surface under the cumulative ranking scores of eleven indicators. Statistical analysis was performed using R statistical software with the GeMTC package based on the Bayesian framework. Results: Six interventions and 667 patients were involved in 18 studies. In comparison with the tooth-anchored groups, the bone-anchored groups showed significantly more increases in Sella-Nasion-Subspinale (°), Subspinale-Nasion-Supramentale(°) and significantly fewer increases in mandibular plane angle and the labial proclination angle of upper incisors. In comparison with the control group, Sella-Nasion-Supramentale(°) decreased without any statistical significance in all treated groups. IMPA (angle of lower incisors and mandibular plane) decreased in groups with facemasks and increased in other groups. Conclusions: Bone-anchored maxillary protraction can promote greater maxillary forward movement and correct the Class III intermaxillary relationship better, in addition to showing less clockwise rotation of mandible and labial proclination of upper incisors. However, strengthening anchorage could not inhibit mandibular growth better and the lingual inclination of lower incisors caused by the treatment is related to the use of a facemask.