• 구강회복응용과학지
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• 제22권1호
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• pp.37-53
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• 2006

Purpose: The purpose of this study was to investigate the influences of the jaw dimension on the bone stress. Materials and Methods: Root analogue implant of Frialit-2 Synchro model in the jaw bone of various thickness from 8mm to 13mm were modelled axisymmetrically for a series of finite element analyses. As load conditions, non-axisymmetric lateral load of 20N and an oblique load of 50N, as well as an axisymmetric vertical load of 50N were taken into consideration. Results: The cervical area of implant under the axisymmetric load and the base cortical bone under the non axisymmetric load condition were the areas of main concern where the higher level of stress were likely to be obtained. Conclusion: The results indicated that at the two concerned areas drastically different stress distribution could take place as a function of the load conditions. Under the vertical load, the lower level of stress was observed for the narrow jaw bone at the cervical cortical bone whereas stress at the base cortical bone remained virtually unchanged. Under the non axisymmetric load condition, however, the stress at the base cortical bone increased very rapidly as the jaw bone width increased without inducing any significant change in the stress level at the cervical area.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권6호
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• pp.477-482
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• 2011

Introduction: Bone regeneration of cystic defects of the jaws after a cyst treatment requires lengthy healing periods. Generally, the bony changes are observed periodically through a visual radiographic reading as well as by the clinical opinion and radiographic images (panorama, periapical view), but it is difficult to compare the objective bony changes using only the radiographic density. In addition, it is difficult to observe minute bony changes through a visual radiographic reading, which can lead to a subjective judgment. This study exmined the bone density after the enucleation of a jaw cyst by fractal analysis. Materials and Methods: Eighteen patients with a cystic lesion on the jaw were assessed. Panoramic radiographs were taken preoperatively, immediately postoperatively, and 1, 3, 6 and 12 months after cyst enucleation. The images were analyzed by fractal analysis. Results: The mean fractal dimensions increased immediately after surgery and 3, 6 and 12 months postoperatively. The postoperative 6 and 12 months fractal dimension was similar to the controls. Conclusion: Fractal analysis was used to overcome the limit of a subjective reading during an assessment of bone regeneration after cyst enucleation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.494-498
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• 2007

Purpose: This study was done to know the usefulness of fractal analysis when evaluating the radiologic changes after decompression on jaw bone cystic lesions using fractal analysis. Materials and methods: 30cases of cystic lesions were followed up after decompression. Panoramic image was used to observe radiologic changes around the cystic lesion. The part of the panoramic image which showed radiologic change was defined as region of interest(ROI); The fractal dimension of the ROI was calculated using box-counting method. Results: Using sign-rank test, there was a statistically significant difference in fractal dimensions after decompression therapy(P<0.0001). The fractal dimensions statistically increased after decompression(the median of D:0.12). Conclusions: The ROI after decompression showed higher fractal dimensions which offer the objective proof of the bone healing around cystic lesions after decompression treatment.

• 대한치과보철학회지
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• 제38권6호
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• pp.814-820
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• 2000

Statement of Problem. Commonly used classification systems do not inform for dentists the dimension of the available bone at a potential implant site although regarding a variety of morphologic and pathophysiologic aspects using schematic graphs. However, for the implantologist the availability of bone substance is most important independent whether it concerns the jaw basis or the alveolus. Purpose of Study. The present article refers to a new evaluation form, to analyze the available bone with regard to optional immediate loading site by site. According to a new systematic implant planning concept will be presented in two case reports. Results. The feasibility of the classification for planning and documentation of immediately loaded implants is presented in two case reports. Conclusion. The factor of bone support for immediate functional stability is important in dental implantology. The new systematic implant planning helps to systematically estimate the dimension (ASCIi classification) of the alveolus site by site to evaluate the possibility of immediate loading. The Gottingen classification thus aids to determine the degree of stability that can be expected for the planned solution.

• Imaging Science in Dentistry
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• 제51권3호
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• pp.323-328
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• 2021

Tooth extraction after head and neck radiotherapy exposes patients to an increased risk for osteoradionecrosis of the jaw. This study reports the results of a radiographic analysis of bone neoformation after tooth extraction in a case series of patients who underwent radiation therapy. No patients developed osteoradionecrosis within a follow-up of 1 year. Complete mucosal repair was observed 30 days after surgery, while no sign of bone formation was observed 2 months after the dental extractions. Pixel intensity and fractal dimension image analyses only showed significant bone formation 12 months after the tooth extractions. These surgical procedures must follow a strict protocol that includes antibiotic prophylaxis and therapy and complete wound closure, since bone formation at the alveolar socket occurs at a slower pace in patients who have undergone head and neck radiotherapy.

• 대한치과교정학회지
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• 제30권6호
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• pp.699-712
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• 2000

림프조직은 비인두 부위에서 Waldeyer's ring의 일부조직으로 tonsil을 이루며 정상적으로 존재한다. 이러한 림프조직이 임상적인 증상을 나타낼 정도로 과증식한 것을 'Adenoid vegetation or Adenoids'라고 이른다. 아데노이드는 일반적으로 유년기에 발생하며 $2\~12$세때 특징적인 증상을 보인다. 사춘기시기에 이르면 절대적인 아데노이드 크기 감소와 주변의 비인두의 성장으로 인한 상대적 크기 감소가 나타난다. 그리하여 성인이 되면 아데노이드는 퇴화된 상태로 변하게 된다. 아데노이드는 구호흡의 주요한 원인 중 하나이며, '아데노이드 얼굴'이라는 특징적인 안면형태를 야기한다고 알려져 있다. 아데노이드에 의한 구호흡이 안면 형태와 치열에 영향을 미칠 수 있다는 주장은 오래 전부터 제기되고 있으나, 여러 가지 복합적인 원인으로 이들간의 상호연관정도를 정확히 알기가 어려웠다. 이에 본 연구에서는 정상 교합 아동에서의 골 연령에 따라 아데노이드와 악골 크기의 정상치와 성장변화량을 제시하고 이들간의 상관관계를 알아보았으며 다음과 같은 결과를 얻었다. 1. 골 연령에 따른 남녀별 계측항목의 평균과 표준편차를 얻었다. 2. 같은 골연령을 비교시 남자는 여자보다 약 2년 가량 성장속도가 느렸다. 3. 비인두의 height과 depth는 남자에서는 CVMI 1과 2 때 많은 성장을 보이고, CVMI 4 이후에서는 성장을 보이지 않았으며, 여자에서는 모든 골 연령에서 유사한 정도의 성장이 나타났다. 4. 비인두의 상대적 면적은 남자에서 CVMI 1에서 2로 이행되는 시기에 유의한 증가를 보였다. 5. 비기도의 상대적 면적과의 상관분석에서 남녀 모두에서 아데노이드 항목중에서는 Ad2와 관련된 항목과 uppe pharynx가 높은 상관관계를 보였으며, 치열궁과 관련된 항목중에는 상$\cdot$하악의 견치간 너비, 상악의 대구치간 너비, 구개정 높이가 상관관계가 있었다.

• Imaging Science in Dentistry
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• 제48권3호
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• pp.153-160
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• 2018

Purpose: This study aimed to assess the reliability of ultrasonography (US) in comparison with cone-beam computed tomography (CBCT) as a tool for monitoring the healing of jaw lesions. Materials and Methods: Twenty-one radiolucent lesions in jaws referred to the Oral Surgery Department at our institution were selected for this study. All lesions underwent CBCT and US examinations. The anteroposterior, superoinferior, and mesiodistal dimensions of the lesions were measured on CBCT and US images before surgery and at 6 months after surgery. The dimensions were compared between the US and CBCT images. Blood-flow velocity around the lesions was measured by color Doppler before surgery and at 1 week and 6 months after surgery to assess the capability of US to show changes in blood-flow velocity around the lesion. Results: Before surgery, there were no significant differences between US and CBCT in the mesiodistal and anteroposterior dimensions, although a significant difference was found in the superoinferior dimension (P<.05). However, at 6 months after surgery, significant differences were found between US and CBCT in all dimensions, and it is likely that the US measurements more accurately reflected the extent of healing. The average blood-flow velocity increased at 1 week after surgery (5.84 cm/s) compared with the velocity before surgery (4 cm/s) (P<.05). Then, at 6 months after surgery, the blood-flow velocity significantly decreased (3.53 cm/s) compared to the velocity measured at 1 week after surgery (P<.05). Conclusion: US with color Doppler was confirmed to be a more efficient tool than CBCT for monitoring bone healing.

• 대한치과보철학회지
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• 제44권2호
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• pp.243-249
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• 2006

Statement of problem: It is important to have a correct presurgical treatment plan before any implant surgery. It must contain substantial information about the patient concerned. However, the standard classification only notifies the dentist about various structural, pathological and physiological dimensions Due to diverse structure of the jaw bone, current standard classification does not tell spatial dimensions of the available bone for implant insertion sites. Purpose of study: The purpose of this study is to report the establishment of the systematic implant treatment plan and its clinical treatment using $Implan^(R)$ program which is based on ASCIi-classification that is available for future diagnosis and scale of treatment and for systematic implant insertion. Results: By assisting the systemic measurement of the available alveolus dimension during implant surgery, it was easy to set initial implant treatment plan. Conclusion: Using $Implan^(R)$ program which is based on ASCIi-classification system that allows the establishment of systemic implant treatment plan and successful clinical performance, it was possible to establish the founding or initial implant treatment plan , the acquisition of information, and the systematization of documentation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권3호
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• pp.233-240
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• 2007

Osteochondroma is a common benign tumor of the axial skeleton, especially the distal metaphysis of the femur and proximal metaphysis of the tibia. However, it occurred rarely on the facial skeleton. The coronoid and condylar processes have been considered to be the most common sites of occurrence for osteochondroma of the facial skeleton. The first treatment of osteochondroma is condylectomy, whereas extirpation was done by excision with condyle salvage. Condylectomy presents decrease of vertical dimension, jaw deviation, malocclusion. So, reconstruction is need. Methods of reconstruction are as follows: no reconstruction, condyloplasty, discectomy, costochondral graft, discplication or coronoidectomy, eminoplasty, alloplastic spacer placement, Le Fort I level maxillary osteotomy, extraoral and intraoral vertical ramus osteotomy. This is a case report of a 28-year old woman who had facial asymmetry, malocclusion and temporomandibular joint pain. We obtained moderate functional and cosmetic results with surgical removal of the osteochondroma by condylectomy and concomitant reconstruction of condyle by vertical ramus osteotomy with sliding technique.

• 대한치과보철학회지
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• 제60권4호
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• pp.382-394
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• 2022

심한 치주염을 가진 환자의 치료는 환자의 개개 치아의 정확한 진단과 전략적인 치료 계획을 통해 단계적으로 진행되어야 한다. 임플란트 지지 고정성 보철 수복은 국소의치에 비해 환자의 만족도가 높고, 안정적인 수직 고경을 유지할 수 있는 장점이 있지만, 경조직이 부족한 다수 치아 결손 부위에서는 심미적인 측면의 실패와 치료 기간이 길어진다는 점의 단점이 있을 수 있다. 또한 통상의 고정성 보철물을 제작하고 장착하는 데에는 일정 기간이 소요되는데, 이 기간 동안 임시 보철물은 치아의 기계적, 생물학적, 심미적 요구 조건을 만족시켜야 한다. 이번 증례 보고에서는 상악과 하악의 부분 무치악 환자에서 단계적인 접근을 통한 임플란트 고정성 보철물을 수복한 증례를 보고하고자 한다.