• 대한골관절종양학회지
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• 제16권2호
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• pp.95-98
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• 2010

활액막성 연골종증은 관절 활액막으로부터 기원하는 증식성의 결절성 연골성 양성 종양이다. 영상의학적 소견은 다양하게 나타나는데 드물게 연골육종, 골육종 그리고 활액 육종과 같은 악성 종양과의 감별을 요하는 수가 있다. 저자들은 컴퓨터 단층 촬영에서는 관절 내 다 발성의 연골성 무기질침착이 뚜렷한 종괴로 인해 활액막성 연골종증을 예상할 수 있으나, 단순 방사선 소견 상 피질골에 근접하고 균질한 방사선비투과의 모습을 보여 방골성 골육종과 유사해 보이는 근위 경골의 후면에 발생한 원발성 활액막성 연골종증 1예를 보고한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.432-439
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• 2012

Purpose: The aim of this study was to investigate the blood supply to the maxillary sinus in Koreans using computed tomography of the lateral wall of the sinus, and to analyze the data according to demographic data, and to compare our results with previously published research. Methods: One hundred and three patients (males 51, females 52) who visited the dental clinic were evaluated. We investigated the canals with cone-beam computed tomography, and measured the diameter and length from the bony notch of the vascular canal at the lateral wall of the sinus to each of the reference planes. Results: Most types of vascular canal were type I & II (total 72.2%) which were driving through inside the sinus wall. Type IV, V were frequently investigated in 1st premolar and 2nd molar. Mean height; from anterior nasal spine-posterior nasal spine plane to vascular canal was 5.56 mm in 1st premolar, 2.11 mm in 2nd premolar, 0.98 mm in 1st molar, 4.32 mm in 2nd molar; from the basal layer of the sinus was 4.93 mm in 1st premolar, 5.00 mm in 2nd premolar, 6.05 mm in 1st molar, 7.91 mm in 2nd molar; and from alveolar crest, 20.80 mm in 1st premolar, 16.57 mm in 2nd premolar, 14.01 mm in 1st molar, 16.17 mm in 2nd molar. The mean height of the vascular canal of each reference plane showed no significant difference between sex, site (left or right) and age. The mean diameters of the canals were 1.76 mm in male, and 1.50 mm in female. Diameter decreased with age, and tooth site (from 1st premolar to 2nd molar). Conclusion: These results show that the mean diameter of the vascular canal of the maxillary sinus varies according to age, sex, and tooth site, but that the mean height of canal had no significant difference based on these three factors.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권4호
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• pp.255-263
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• 2011

Introduction: Maxillomandibular fixation (MMF) is essential before surgery under general anesthesia in maxillofacial trauma patients. MMF is used basically to reconstruct the occlusion and occlusal stability to recover the facial shape and oral functions. The arch bar and wire is a traditional method for MMF, but it can not only bring pressure to the periodontal ligaments and teeth but also cause a penetrating injury to the surgeons. Materials and Methods: In this study, 198 patients with an open reduction using a manual reduction without MMF from September 2005 to May 2010 in Dankook University Dental Hospital were subjected to a follow-up evaluation during the postoperative 4 months periods. This study evaluated the incidence of complications according to the condition of the patient (gender, age), the state of bony union of the fracture sites and a numeric rating scale evaluation for postoperative pain scoring. Results: 1. The complications were classified into major and minor according to the seriousness, and the major complication rate was as low as 2.02%. Only 2 cases of re-operations (1.01%) were encountered. In the classification according to the fracture line, plate fracture was observed in both cases of mandibular symphysis fracture, and angle fractures and loosening of two screws were noted in the case of mandibular angle fracture. 2. The complication rate was similar regardless of gender and age. 3. The degree of bony union was satisfactory, and the complication rate was reduced as the bony union improved. 4. More patients complained of pain as the operation time was increased. Conclusion: The use of MMF is not always necessary if a skilled assistant is provided to help manually reduce the fracture site. Compared to other studies of mandibular fracture surgery using MMF, the complication rate was similar using only manual reduction and the patients' discomfort was reduced without MMF.

• 전기학회논문지
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• 제65권5호
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• pp.730-737
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• 2016

Electric utilities may face new threats with increase in electric vehicles (EVs) in the personal automobile market. The peak demand will increase which may stress the distribution network equipment. The focus of this paper is on an adaptive control of smart household appliances by using an intelligent load management system (ILMS). The main objectives are to accomplish consumer needs and prevent overloading of power grid. The stress from the network is released by limiting the peak demand of a house when it exceeds a certain point. In the proposed strategy, for each smart appliance, the customers will set its order/rank according to their own preferences and then system will control the household loads intelligently for consumer reliability. The load order can be changed at any time by the customer. The difference between the set and actual value for each load's specific parameter will help the utility to estimate the acceptance of this intelligent load management system by the customers.

• 전기학회논문지
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• 제65권12호
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• pp.1958-1964
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• 2016

AC railway feeding system use single phase to supply power to the railway vehicles. And the system use the rail track as a return current path, so that current flows in the rail. In this situation inductive interference on communication system and unsafe environment can appear on railway system. Therefore knowing the current distribution of catenary system and analysing the return current is required. In this study detail return current distribution was analyzed by modeling the catenary system as 4-conductors group. The distribution characteristics and trends of return current were studied by using the PSCAD/EMTDC and FDTD method that based on Maxwell equation was used to calculate the induced voltage. Simulation code was made by MATLAB. Using this study result data, we can suggest the proper installation location of digital device and these data can be used for additional studies related to return current or induced voltage as a base data.

• 식물분류학회지
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• 제50권1호
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• pp.84-88
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• 2020

그동안 한국 내 분포 및 분류학적 실체가 모호했던 식물, 납작하늘지기절(F. sect. Fuscae)의 바람개비하늘지기 [Fimbristylis fimbristyloides (F. Muell.) Druce] (사초과)를 전라남도 신안군 암태도의 바닷가 주변의 산자락 습한 곳에서 발견하였다. 바람개비하늘지기는 1년생으로 줄기는 5-15 cm 정도에 불과한 작은 식물로 소수가 옆으로 납작한 점에서 속내 대부분의 식물들과 크게 다르다. 특히, 바람개비하늘지기는 쇠하늘지기와 비슷하지만 식물체의 높이, 엽신, 화서당 소수의 수와 크기, 화주의 털 유무, 수과의 크기 및 자루의 유무 등에 의해 구별된다. 바람개비하늘지기에 대한 기재, 근연종과 차이점, 검색표 및 사진 등을 제시하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권1호
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• pp.33-41
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• 2007

Bone scan using radioactive isotope can be more effective than conventional X-ray radiograph for finding jaw lesion because it takes an image of the physiologic change of bone. This study is designed to show how available bone scan is able to diagnose jaw lesion better than simple X-ray and CT, as well as to determine a basis of diagnosis for jaw lesion using bone scan. The 77 patients, visiting the Oral & Maxillofacial Surgery, Department of Dankook University Hospital from January 2002. to August 2005. who were diagnosed histopathologically with postoperative malignant tumor, osteomyelitis, and bone infiltrative benign disease. Preoperative X-ray, CT, bone scan were taken and were compared with histopathologic finding. Also to compare specificty of each lesion in bone scan, bone density was measured to compare. The results were as follows. 1. Among the 25 cases of oral malignant tumor of bony invasion, a positive diagnosis associated with histopathologic evaluation, 22 cases(88%) in bone scan, 14 cases(56%) in CT image, and 10 cases40%) in simple X-ray. 2. Among the 31 cases of osteomyelitis, a positive diagnosis associated with histopathologic evaluation, 30 cases(97%) in bone scan, 23 cases(74%) in CT image, and 19 cases(61%) in simple X-ray. 3. Among the 11cases of bone infiltrative benign disease, a positive diagnosis associated with histopathologic evaluation, 11 cases(100%) in bone scan, 10 cases(91%) in CT image, and 6 cases(55%) in simple X-ray. 4. Measurement of bone density in each group showed no statistical significant difference between malignant tumor and osteomyelitis as well as benign bone disease. But, a statistical significance was seen between osteomyelitis and benign bone disease. From this results, bone scan are more sensitive than simple X-ray and CT image in jaw lesion diagnosis, but specificity shows no significant difference. Therefore, it should be suggested that evaluation of bone scan must be carrying out in reference to final histopathologic diagnosis.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권1호
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• pp.18-26
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• 2009

Purpose: Recently, the role of serum tumor marker has been studied for an important issue on diagnosing and treating tumors in the head and neck region because tests using tumor markers need relatively simple procedures and are acceptable to patients, compared with other test methods. Tumor marker tests were performed on patients with squamous cell carcinoma, which were known to have the highest prevalence among tumors in the head and neck region. Association between each tumor marker, and diagnosis and prognosis of tumors was assessed. Materials and methods: Tumor marker tests were carried out on 31 patients who visited Oral and Maxillofacial Surgery Department in Dankook University Dental Hospital between January 2003 and August 2008 and who were diagnosed as primary oral squamous cell carcinoma through out histopathologic diagnosis. Blood sample from these patients was performed to measure tumor markers using nuclear medicine diagnostic equipment. Measured entries were as follows: PSA(prostate-specific antibody), SCCAg( Squamous Cell Carcinoma Related Antigen), CA 19-9(Cancer Antigen 19-9), Ferritin, $\alpha$- FP(Alpha-Fetoprotein), Cyfra 21-1, CA125 (Cancer Antigen 125) and p53. Results: Analyses on each tumor marker indicated that squamous cell carcinoma in the head and neck region had statistically significant correlation with p53, SCC-Ag(TA-4), Cyfra 21-1 and Ferritin. p53 demonstrated the highest sensitivity. Especially, 4 cases among 18 cases which Ferritin was measured exhibited metastasis. In all those 4 cases, Ferritin values were higher than the standards (15 - 332ng/ml). Therefore, Ferritin is considered to have a close relation with metastasis of squamous cell carcinoma. Conclusion: This study shows that tumor marker tests are more useful in evaluating progression and prognosis of tumors rather than in diagnosing them. Particularly, serum Ferritin is considered to be beneficial in assessing metastasis of squamous cell carcinoma in the head and neck region and in developing treatment plans based on the assessment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권1호
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• pp.27-34
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• 2009

Angiogenesis is essential for solid tumor growth and progression. Among the pro-angiogenetic factors, vascular endothelial growth factor(VEGF), also known as vascular permeability factor, is the most important as a mitogen for vascular endothelium. The VEGF family of molecules currently consists of six growth factors, VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-E, and placenta growth factor(PlGF). Over-expression of PlGF is associated with angiogenesis under pathological conditions such as ischemia, inflammation, and cancer. Hence, the goal of this study is to identify the correlation of clinicopathlogical factors and the up-regulation of PlGF expression in oral squamous cell carcinoma. We studied the immunohistochemical staining of PlGF, PlGF gene expression and a real time quantitative RT-PCR in 20 specimens of 20 patients with oral squamous cell carcinoma. The results were as follows. 1. In the immunohistochemical study of poorly differentiated and invasive oral squamous cell carcinoma, the high level staining of PlGF was observed. And the correlation between immunohistopathological PlGF expression and histological differentiation of specimens was significant (Pearson correlation analysis, significance [r] >0.6, P < .05). 2. In the PlGF gene RT-PCR analysis, PlGF expression was more in tumor tissue than in adjacent normal tissue. Paired-samples analysis determined the difference of PlGF mRNA expression level between the cancer tissue and the normal tissue (Student's t - test, P < .05) These findings suggest that up-regulation of the PlGF gene may play a role in progression and local metastasis in invasive oral squamous cell carcinoma.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.464-469
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• 2007

The bone graft materials are grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Among the various allogenic graft materials, hydroxyapatite($Ca_{10}(PO_4)_6(OH)_2$, HA), the main inorganic phase of human hard tissue, is widely used as a repair material for bones. When HA applied to bony defect, however, it may be encapsulated with fibrous tissue and floated in the implanted area by the lack of consolidation. Fluoridated hydroxyapatite($Ca_{10}(PO_4)_6(OH)_2$, FHA), where F- partially replaces the OH- in the hydroxyapatite, is considered as an alternative material for bone repair due to its solubility and biocompatibility. This study was designed to find out the bone healing capacity of FHA newly produced as a nanoscale fiber in the laboratory. We implanted HA and FHA in the rabbit cranium defect and histologically analysed the specimen. The results were as follows. 1. In the 4 weeks, fibrous connective tissue and little bone formation around materials of the experimental group I implanted HA were observed. In the experimental group II implanted FHA, newly formed bone around materials were observed. 2. In the 8 weeks, the amount of newly formed and matured bone of the experimental group II was more than the experimental group I and control group. From the results obtained, we suggest that FHA, newly synthesized, is relatively favorable bone substitute with bioconpatibility and has better bone healing capacity than pure HA.