• 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.

• Journal of Periodontal and Implant Science
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• 제28권1호
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• pp.71-86
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• 1998

The purpose of this study was to evaluate clinically and histopathologically the effects to the periodontal tissue in rats after Cyclosporin A (CsA) administration and to determine whether there is a relationship between dosage of CsA or blood CsA level and the seventy of gingival overgrowth in rats. Twenty 6-week-old Sprauge-Dawley Fats were randomized into 4groups. The control group received olive oil only and the test group received daily CsA in olive oil via gastric feeding for 6weeks at a 3,10, and 30mg/kg. Rats were weighed to evaluate the systemic effect of drug and stone models were made from alginate impressions of upper and lover anterior region at 2 week interval. On completion of offal CsA administration, blood were collected and blood CsA levels were quantitated by TDxFLx analyzer. Rats were sacrificed an6 their upper and lower jaws were removed together with the surrounding gingiva and soft tissue for light microscopic examination. The results were as follows : 1. The weight gain of GsA-treated rats was much less than of the control group and central incisors were gradually displaced and separated in the test groups. 2. The extensive fibrovascular proliferation and scattered inflammatoy infiltrates in an edematous stroma were observed in enlarged gingiva of CsA-treated rats. 3. The increase in buccolingual, mesiodistal dimension of the anterior teeth and vertical height of the interdental papilla showed dose-dependent manner in CsA-treated rats. 4. Significant positive correlation exists between blood CsA level and the severity of gingival overgrowth in anterior teeth. This result indicates that the severity of gingival enlargement in CsA treated rats is correlated with dosage of CsA administration and blood CsA level.

• 대한소아치과학회지
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• 제25권2호
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• pp.268-276
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• 1998

낭종은 환자의 연령, 낭종의 종류 및 위치에 따라 치료방법을 선택하는 것이 바람직하며, 환자의 연령이 어린 경우에는 조대술을 통하여 낭종에 이환된 치아를 가능한 보존시키는 것이 바람직한 것으로 생각된다. 낭종에 포함되었던 치아는 조대술로 낭종을 제거후에 생리적인 맹출이 이루어지는 것을 관찰할 수 있었으며 기능도 정상적으로 수행하는 것으로 판단된다. 그러나, 조대술을 이용하여 시술한 후에는 맹출된 치아에 병리조직이 잔존되어 재발의 가능성이 있으므로 주기적인 관찰이 요구될 것으로 생각된다.

• 구강회복응용과학지
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• 제17권2호
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• pp.75-84
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• 2001

The purpose of this study is to to analyze the mechanical stress on articular disk of the dentated skull with the condition of unilateral posterior molar missing. For this study, the three dimensional finite element model of human skull scanned by means of computed tomography. (G.E. 8800 Quick, USA) was constructed. The finite element model of jaws is composed of 98,394 elements and 38,321 nodes, and it consists of articular disc, maxilla, mandible, teeth, periodontal ligament and cranium. Boundary condition included rigid restraints at the first molar and endosteal cortical surfaces of the insertion points of temporal bone. The data derived from Nelson's study were used for the loading conditions of mandible during clenchings and for maxilla, new loading and constraint conditions were applied. A clenching task during intercuspal position was modeled to the three dimensional finite element model. The stress level and displacement of articualr disc on the model with unilateral posterior molar missing under bilateral clenching task can be analyzed. During bilateral clenchings, the compressive stress level and diplacement of the articular disk on the side of unilateral posterior molar missing is greater than that on the case with full dentition, whereas a higher stress was found on the disk on the balancing side of the full dentition. Although this kind of study is not enough to explain the role of occlusion as an etiologic factor of TMD, there may be a possibiliy that the condition of posterior molar missings may contribute in part to the TMJ biomechanics.

• Imaging Science in Dentistry
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• 제42권4호
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• pp.231-235
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• 2012

Purpose: This study was performed to evaluate the trabecular pattern on panoramic radiographs to predict age-related osteoporosis in postmenopausal women. Materials and Methods: Thirty-one postmenopausal osteoporotic women and 25 postmenopausal healthy women between the ages of 50 and 88 were enrolled in this study. The bone mineral density (BMD) of the lumbar vertebrae and femur were calculated using dual-energy X-ray absorptiometry (DXA), and panoramic radiographs were obtained. Fractal dimension (FD) was measured using the box counting method from 560 regions of interest ($51{\times}51$ pixels) in 6 sites on the panoramic radiographs. The relationships between age and BMD and between FD and BMD were assessed, and the intraobserver agreement was determined. Results: There was a significant difference in the FD values between the osteoporotic and normal groups (p<0.05). There was a significant difference in the FD values at three sites in the jaws (p<0.05). Age was significantly correlated with the BMD measurements, with an odds ratio of 1.25. However, the FD values were not significantly correlated with the BMD measurements, with an odds ratio of 0.000. The intraobserver agreement showed relatively higher correlation coefficients at the upper premolar, lower premolar, and lower anterior regions than the other sites. Conclusion: Age was an important risk factor for predicting the presence of osteoporosis in postmenopausal women. The lower premolar region was the most appropriate site for evaluating the FD value on panoramic radiographs. However, further investigation might be needed to predict osteoporosis using an FD value on panoramic radiographs.

• Imaging Science in Dentistry
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• 제40권4호
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• pp.159-163
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• 2010

Purpose : This retrospective study was performed to investigate the prevalence of the idiopathic osteosclerosis (IO) in Korean malocclusion patients according to age, sex, and the Angle's classification of malocclusion. Materials and Methods : This study consisted of 2,001 randomly selected patients from the Department of Orthodontics at the Gangneung-Wonju National University Dental Hospital, Korea. The prevalence of IO in Korean malocclusion patients was recorded using their panoramic radiographs, and the following parameters were surveyed; age, sex, and the Angle's classification of malocclusion. The chi-square test was analyzed to determine the statistical significance of differences in the prevalence of IO between age, sex, and the Angle's classification of malocclusion. Results : The prevalence of IO in the jaws was 6.7% in a total of 2,001 examined orthodontic patients. The majority of IO was found in the mandible (96.58%). The 30-39 age group showed the highest prevalence of IO (9.60%). There was a higher prevalence in females (6.89%) than in males (6.45%). The prevalence of IO in Angle Class I group (7.07%) was the most frequent, followed by Angle Class II group (6.72%), and Angle Class III group (6.40%). However, there was no statistical significance in sex and Angle's classification of malocclusion. Conclusion : The prevalence of IO in malocclusion patients showed the differences between various age groups and most of them were found in the mandibular posterior area. However, sex and the type of malocclusion are not to be considered as a contributing factor of IO.

• 대한치과보철학회지
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• 제45권6호
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• pp.760-768
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• 2007

Statement of problem. Conventional denture treatment for totally edentulous patients is associated with a variety of functional and psychosocial problems. The placement of implants in the anterior region of the maxilla and mandible and the fabrication of an implant-retained overdenture might solve these problems. Purpose. This study compared the marginal bone loss around the implant and evaluated the implant survival rate and complications in patients treated with overdentures retained by implants for 2 years. Material and methods. Patients who had received implant-retained overdentures using a Dolder bar at Samsung Medical Center from January 1999 to June 2005 and had participated in the annual recall programs for two years were selected for this study. A total of 18 patients and 56 $Br{\aa}ne-mark\;system^{(R)}$ implants were used, and their data were reviewed. Evaluations of the survival rate, bone quality, marginal bone loss, and complications were performed. The data on the Dolder bar length and clip length were measured. The change in marginal bone loss and the correlation between the marginal bone loss and bar length, clip length, or bone quality were investigated. Results. Implants placed in this study showed a 100% survival rate. The average annual bone loss was 1.12mm in the first year and 0.27mm in the second year in the maxilla, and 0.58mm in the first year and 0.22mm in the second year in the mandible. The marginal bone loss in the maxilla showed no significant association with those in the mandible. (P>.05). There was no significant difference in marginal bone loss around implants between the first and second year. (P>.05) There was no statistically significant relationship (P>.05) between the marginal bone loss and bone quality, clip length, or Dolder bar length. The Dolder bar length showed a high correlation with the clip length. (P<.05) Various complications were noted. Conclusion. These results confirmed the favorable outcome for patients treated with implant-retained overdentures.

• 대한소아치과학회지
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• 제28권2호
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• pp.287-292
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• 2001

Burkitt림프종은 중앙아프리카 지역의 어린이 악골에서 흔하게 나타나는 악성 종양으로 림프조직으로부터 발생되며 매우 빠른 성장 양상을 보인다. 임상적으로는 3~8세 아동에 주로 호발하며 악골에 발생하는 경우 안면부 종창이 나타날 수 있으며 유치의 비정상적 동요 및 구치부 조기 맹출등이 나타날 수 있다. 방사선 소견으로는 경계가 불규칙한 방사선투과성 병소로 나타나며 조직학적으로는 종양세포들 사이에 대식세포가 분포되어 "starry-sky" appearance의 특징적인 양상이 관찰된다. 본 증례는 좌측 안면부 종창을 동반한 유구치의 심한 동요도를 주소로 내원한 3세 남환아에서 임상 및 방사선 검사와 조직학적 검사를 통해 Burkitt림프종으로 진단하였고 항암 화학요법에 의해 치료중이며 양호한 치료 결과를 얻고 있다.

• 대한치과의사협회지
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• 제55권11호
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• pp.778-788
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• 2017

Ultrasound sonography(US) is used to evaluate various diseases of oral and maxillofacial region including salivary glands, soft tissue and jaw lesions because of easy accessibility and no hazard of ionizing radiation. Also, US can offer dynamic study showing real-time images during diagnostic or surgical procedure. US images provide accurate information about the internal features of lesions on the jaw prior to surgical treatment. Doppler images are used to visualize the vascular distribution of the lesions and to provide additional information to enhance diagnostic value. It is necessary to evaluate the diagnostic value of US and evaluate its usefulness by looking at clinical cases using US images. Therefore, US imaging may be recommended as an assistant image in evaluating jaw lesions. US images provided accurate information about the internal structure of lesions on the jaw prior to surgical treatment, and diagnostic value was enhanced by visualizing the vascular distribution of the lesion using doppler imaging. We report the protocol and suggest the effectiveness of US for various lesions and US-guided sialography.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제14권1_2호
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• pp.117-123
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• 1992

우측 협부의 종창과 압통을 주소로 내원한 59세의 여자 환자에서 방사선 소견상 우측 상악골의 광범위한 골파괴상이 나타났고 조직생검에서 MFH로 진단되었다. 치료는 술전과 술후에 SWOG외 CY-VA-DIC요법을 변형시킨 화학요법과 총 40Gy의 $^{60}Co$ 방사선요법 그리고 우측 상악골전적출술의 삼자병용요법을 시행하였다. 술후 2년이 경과된 현재까지 재발이나 전이 등의 소경은 관찰되지 않고 있으며 환자의 예후에 대하여 주의 깊은 관찰을 계속하고 있다.