하악골에 발생한 변연성골종

허민석,안창현,박태원,이삼선,최순철 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.2

Purpose: To determine the clinical and radiological feature of peripheral osteoma of the mandible (POM) in a Korean population and to compare with previous reports. Materials and Methods: Sixteen cases of POM found in 15 Korean patients who visited Seoul National University Dental Hospital between 1980 and 1998 were reviewed to determine their clinical and radiological features. Results: The 15 patients, five males and ten females, ranged in age from 22 to 69 years, with a mean age of 40.7 years. Six POMs were located on the buccal side of the mandibular body and five on the lingual aspect of the mandibular body and five on the lower border of the mandible. The duration of the lesion ranged between 1 and 10 years. The size of the lesions, in their great diameter, ranged from 6 to 26 mm, with a mean of 14.1 mm. Six POMs were pedunculated, nine sessile, and one bell-shaped. Eleven POMs were compact types and five were cancellous ones. Conclusion: The clinical and radiological features of these Korean series were broadly consistent with those of non-Korean populations reported previously. The principal difference was that all POMs under 35 year-old age were compact types.(J Korean Oral Maxillofac Radiol 1999;29:523-532)

측두하와에 발생한 악성 섬유성 조직구종

허민석,이삼선,최순철,이경희 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.2

Malignant fibrous histiocytoma is one of the most common soft tissue sarcomas in late adult life, but its incidence in oral and maxillofacial region is extremely rare. We report a case of malignant fibrous histiocytoma which occurred in the infratemporal fossa. Conventional radiograph of this case showed an ill-defined radiolucent lesion in the alveolar bone of the right maxillary first molar area, the lateral wall of the maxillary sinus, and the ascending ramus of mandible. MRI demonstrated a well defined mass of intermediate signal intensity in T1 weighted images but T2 weighted images showed two distinctive regions of different characteristics. Upper portion of the lesion was of hyperintense signal but (at) lower protion, the signal intensity decreased clearly, which might mean that this lesion(mass) is composed of two different subtypes though it couldn't be confirmed by histopathological examination. Biopsy was taken the lesion as only in the soft tissue of the maxillary posterior alveolar region and confirmed the storiform-pleomorphic type of malignant fibrous histiocytoma. Histopathological subtype was well consistent with the relatively aggressive imaging findings of that region. We expect more detailed analysis of the nature of malignant fibrous histiocytoma with improvement of the imaging modality and the identification of the relationship between diagnostic imaging and histopathologic findings.(J Korean Oral Maxillofac Radiol 1999;29:533-548)

편평세포암종 임파절 전이에 대한 인공 신경망 시스템의 진단능 평가

허민석,박태원,박상욱,유동수,이삼선,최순철 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.1

Purpose: The purpose of this study was to evaluate cervical lymph node metastasis of oral squamous cell carcinoma patients by MRI film and neural network system. Materials and Methods: The oral squamous cell carcinoma patients(21 patients, 59 lymph nodes) who have visited SNU hospital and been taken by MRI, were included in this study. Neck dissection operations were done and all of the cervical lymph nodes were confirmed with biopsy. In MR images, each lymph node were evaluated by using 6 MR imaging criteria(size, roundness, heterogeneity, rim enhancement, central necrosis, grouping) respectively. Positive predictive value, negative predictive value, and accuracy of each MR imaging criteria were calculated. At neural network system, the layers of neural network system consisted of 10 input layer units, 10 hidden layer units and 1 output layer unit. 6 MR imaging criteria previously described and 4 MR imaging criteria (site I-node level II and submandibular area, site II-other node level, shape I-oval, shape II-bean) were included for input layer units. The training files were made of 39 lymph nodes(24 metastatic lymph nodes, 10 non-metastatic lymph nodes) and the testing files were made of other 20 lymph nodes(10 metastatic lymph nodes, 10 non-metastatic lymph nodes). The neural network system was trained with training files and the output level (metastatic index) of testing files were acquired. Diagnosis was decided according to 4 different standard metastatic index-68, 78, 88, 98 respectively and positive predictive values, negative predictive values and accuracy of each standard metastatic index were calculated. Results: In the diagnosis of using single MR imaging criteria, the rim enhancement criteria had highest positive predictive value (0.95) and the size criteria had highest negative predictive value(0.77). In the diagnosis of using single MR imaging criteria, the highest accurate criteria was heterogeneity (accuracy : 0.81) and the lowest one was central necrosis (accuracy : 0.59). In the diagnosis of using neural network systems, the highest accurate standard metastatic index was 78, and that time, the accuracy was 0.90. Neural network system was more accurate than any other single MR imaging criteria in evaluating cervical lymph node metastasis. Conclusion: Neural network system has been shown to be more useful than any other single MR imaging criteria. In future, Neural network system will be powerful aiding tool in evaluating cervical node metastasis.

정상 이하선의 전산화단층사진상의 프랙탈차원에 관한 연구

허민석,유동수,이상진 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.1

Purpose: This study was to investigate the age and sex differences of the fractal dimension of the normal parotid glands in the digitized CT images. Materials and methods: The six groups, which were composed of 42 men and women from 20 s, 40's and 60's and over were picked. Each group contained seven people of the same sex. The normal parotid CT images were digitized, and their fractal dimensions were calculated using Scion Image PC program. Results: The mean of fractal dimensions in males was 1.7292(±0.0588) and 1.6329(±0.0425) in females. The mean of fractal dimensions was 1.7617, in young males 1.7328 in middle males, and 1.6933 in old males. The mean of fractal dimensions was 1.6318, in young females 1.6365 in middle females, and 1.6303 in old females. There was no statistical difference in fractal dimension between left and right parotid gland of the same subject(P>0.05). Fractal dimensions in male were decreased in older group(P<0.05) and larger than female in same age group(P<0.05). But fractal dimensions in female had a tendency to decrease in older group but no statistical difference between ages(P>0.05). Conclusions: The fractal dimension of parotid glands in the digitized CT images will be useful to evaluate the age and sex differences.(J Korean Oral Maxillofac Radiol 1999:29:201-206)

인공적 인접면 치아우식증의 구내방사선사진과 디지탈 영상의 진단능 평가

허민석,유동수 大韓口腔顎顔面 放射線學會 1994 Imaging Science in Dentistry Vol.24 No.2

Recently, the digital image was introduced into radiological image. The digital image has the power of contrast enhancement, histogram control, and other digitally enhancement. At the point of the resolution, periapical radiograph is superior to the digital image, but enhanced digital procedure improves the diagnostic ability of the digital image. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries in conventional radiographs, digital radiographs and enhanced digital radiographs (histogram specification). ROC(Receiver Operating Characteristic) analysis and paired t-test were used for the evaluation of detectability, and following results were acquried: 1. The mean ROC area of conventional radiographs was 0.9274. 2. The mean ROC area of unenhanced digital image was 0.9168. 3. The mean ROC area of enhanced digital image was 0.9339. 4. The diagnostic ability of three imaging methods was not significant difference(p>0.05). So, the digital images had similar diagnostic ability of artificial proximal caries to conventional radiographs. If properly enhanced digital image, it may be superior to conventional radiographs.

디지털공제방사선촬영술을 이용한 치근단 흡수의 평가

허민석,이삼선,이경희,최항문,최순철,박태원 대한구강악안면방사선학회 2001 Imaging Science in Dentistry Vol.31 No.1

Purpose : This study was performed to compare the diagnostic ability of conventional intraoral radiographs with that of digital subtraction image and to assess the quantifying ability of digital subtraction image for simulated apical root resorption Materials and Methods : Conventional intraoral radiographs and digital images of ten sound maxillary central incisors and those with simulated apical root resorption were taken with varying horizontal and vertical angulations of the x-ray beam. The diagnostic accuracy to detect the lesion was evaluated on conventional intraoral radiographs and digital subtraction images by ROC analysis. The amount of simulated apical root resorption was also estimated on the reconstruction images by Emago□ and compared with actual amount of tooth loss using paired t-test. Results : The diagnostic accuracy of conventional intraoral radiographs to detect the apical root resorption was low(ROC area = 0.6446), and the sensitivity and the specificity of digital subtraction images were 100%, respectively. The calculated amounts of apical root resorption showed no statistically significant difference with the actual amounts of the lesion (p 〉 0.05). Conclusion : Digital subtraction radiography is powerful tool to detect the small apical root resorption, and quantitative analysis of small amounts of the lesion can be evaluated by digital subtraction radiography.(Korean J Oral Maxillofac Radiol 2001;31:51-5)

하악골에 발생한 평활근육종

허민석,이진,박태원,이삼선,최순철 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.2

Leiomyosarcoma is extremely rare in the oral cavity and especially in the mandible. At first, the case of this report was diagnosed as odontogenic fibroma but after approximately 3.5 years, it was diagnosed as leiomyosarcoma. Conventional radiograph of the first time showed an ill-defined radiolucent lesion in the mandible. After local recurrence, CT images showed a large irregular soft tissue mass with some necrotic areas. These findings were not specific for leiomyosarcoma, but they suggested that this lesion was a recurrent soft tissue sarcoma. Histopathological examinations using H & E staining, immunohistochemical staining and Masson's trichrome staining confirmed this case as leiomyosarcoma. Deciding its malignancy or benignancy, defining the tumor extent and its relationship to the surrounding anatomic structures, and evaluating the distant metastasis are more important roles of radiographic examination than finding out the name of disease.(J Korean Oral Maxillofac Radiol 1999;29:549-560)

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.

DMBA 유도 햄스터 협낭암 발생과정에서 방사선 조사가 증식세포핵항원(PCNA)의 발현과 apoptosis 유발에 미치는 영향

전인성,허민석,최항문,이삼선,최순철 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.3

Purpose : This study was carried out to investigate the effect of irradiation on the expression of proliferating cell nuclear antigen (PCNA) and apoptosis induction during the carcinogenesis in hamster buccal pouch. Materials and methods : Three months old Syrian golden hamsters were divided into control and 2 experimental groups, Hamsters in control group were left untreated on buccal pouchs. Twenty four hamsters were treated with 0.5% DMBA tri-weekly on the right buccal pouch. Forty eight hamsters were treated with 0.5% DMBA tri-weekly and irradiated with the dose of 5 Gy and 10 Gy at 6,9, 12, 15 weeks after DMBA application. Resected buccal pouches were sectioned and examined for potential expression pattern of PCNA and apoptosis. Results : The PCNA index was increased with the stages of buccal pouch epithelium carcinogenesis except the hyperplasia stage in control group (p< 0.05). The irradiation did not effect on the PCNA index in the dysplasia and the carcinoma in situ stage, but in the hyperplasia stage, the PCNA index was increased with 10 Gy radiation and decreased in the carcinoma stage (p< 0.05). The apoptotic index was significantly decreased from the carcinoma in situ stage and the lowest in the carcinoma stage, The apoptotic index was significantly decreased in the hyperplasia and dysplasia stage with the 5 Gy irradiation and significantly increased only in the carcinoma stage with the 10 Gy irradiation (p< 0.05). Conclusion : The PCNA and apoptotic index were varied according to the irradiation period and dosage in each carcinogenesis stage. (Korean J Oral Maxillofac Radiol 2000; 30: 207-216)

수 종의 상피기원 종양 세포주에서 방사선 조사와 표피성장인자 투여에 따른 세포 주기의 변화와 apoptosis 유발에 관한 연구

한원정,허민석,이삼선,최순철,박태원 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.1

Purpose : This study was aimed to evaluate the cell cycle arrest and apoptosis induction after irradiation and epidermal growth factor(EGF) treatment in three human epithelial tumor cell lines (A43l, Siha, KB). Materials and Methods : Single irradiation of 2, 5 and 10 Gy was done on three cell lines with 5.38 Gy/min dose rate using Cs-137 irradiator at room temperature. Also, EGF of 10 ng/ml was added immediately after 10 Gy irradiation. Cell growth was evaluated by counting the living cell number using a hemocytometer at 1 day, 2 days, 3 days, 4 days and 5 days after irradiation. Cell cycle arrest and apoptosis induction were assayed with the flow cytometry at 8 hours, 12 hours, 1 day, 2 days, 3 days, 4 days and 5 days after irradiation. Results : Growth of irradiated three cell lines were inhibited in proportion to radiation dose, EGF treatment after irradiation showed various results according to cell lines. On all cell lines, G2 arrest was detected after 8 hours and maximized after 12 hours or 1 day. Amount of G2 arrest was positively dose dependent. However, EGF showed no significant change on G2 arrest. G2 arrest was recovered with time at 2 Gy and 5 Gy irradiation. However, at 10 Gy irradiation, G2 arrest was continued. Apoptosis was detected at 10 Gy irradiation. On EGF treated group after irradiation, A431 and Siha cell lines showed slightly increased apoptosis but there was no statistically significant difference. KB cell line showed no marked change of apoptosis induction. Conclusion : Irradiation effects on cell cycle arrest and apoptosis induction in three human epithelial tumor cell lines, however epidermal growth factor doesn't effect on. (Korean J Oral Maxillofac Radiol 2000; 30: 71-79)