구내 표준 방사선사진을 이용한 구내방사선촬영기의 선질 평가

이상섭,권혁락,심우현,오승현,이지연,전국진,김기덕,박창서 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.3

Purpose : This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. Materials and Methods : The study was done using the intraoral X-ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Results : Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-705 model of prosthodontic dentistry department, and the REX601 model at the student clinic were relatively low. Conclusion : HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion. (Korean J Oral Maxillofac Radiol 2000; 30: 183-188)

구내방사선사진의 인접면 치아우식 진단에 대한 유용성 평가

김영희,강병철 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.1

Purpose : To compare the diagnostic performance of clinical and radiologic examination for the interproximal caries on intraoral periapical radiographs and to evaluate the value of periapical radiographs. Methods : One hundred seven dental patients were examined clinically, with a mouth mirror and an explorer, by a dentist at the department of oral medicine, and the presence or absence of interproximal caries lesion was recorded. The patients were prescribed one or more dental peuapical radiographs. Radiographs were assessed for the presence of interproximal caries by three oral and maxillofacial radiologists independently. Two thousand sixty interproximal surfaces were included in this study. The diagnostic accuracies of clinical and radiologic examinations for interproximal caries were calculated. To assess the degree of agreement between clinical and radiologic examinations, Cohen's coefficient of agreement was computed. Results : The specificity of clinical and radiologic examination was 0.991,0.997 and the sensitivity was 0.279, 0.985 respectively. The diagnostic accuracy of radiologic examination was statistically significantly higher than that of clinical examination (P< 0.05). Cohen's kappa value of clinical and radiologic examination was 0.335,0.942 respectively. These results suggested that clinical examination show only fair agreement, whereas radiologic examination show perfect agreement. Conclusion : The diagnositic performance of the dental periapical radiographs on interproximal caries were higher than that of clinical examination, thus this study showed the validity of periapical radiographs for detecting interproximal caries lesion without bitewing radiograph. (Korean J Oral Maxillofac Radiol 2000; 30: 49-54)

뼈흡수유도호르몬이 ROS17/2.8세포로부터 Nitric Oxide 형성에 미치는 영향

고선일,김민성,한원정,김세원,김정근 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Purpose : We performed the present study to investigate whether osteotropic hormomes play roles on the nitric oxide (NO) production in culture of ROS17/2.8 osteoblastic cells. Materials and Methods : The osteoblastic cell line ROS17/2.8 cells were cultured in F12 medium supplemented with 5% fetal bovine serum (FBS) at 37?C in a humidified atmosphere of 5% CO₂ in air. ROS17/2.8 cells were plated in 96-well plates at a density of 2-3×10³ cells/well and grown to confluence. Then the cells were pretreated with osteotropic hormones (parathyroid hormone (PTH) 20-500 ng/mL, 1,25 dihydroxycholecalciferol (1,25[OH]₂D₃) 1-100 nM; prostaglandin E₂ (PGE₂) 20-500 ng/mL) in the medium supplemented with 0.4% FBS for 72 hours and the cells were treated with cytokines (TNFα and IFNγ) in phenol red-free F12 medium for an additional 48 hours. NO synthesis was assessed by measuring the nitrite anion concentration, the reaction product of NO, in the cell culture medium using Griess reagent. Results : PTH and 1, 25[OH]₂D₃ pretreatment induced a significant increase in NO production in the presence of TNFα and IFNγ. PGE₂ slightly induced NO production compared to the control group. But, PGE2 pretreatment did not affect in NO production in the presence of TNFα and IFNγ. Conclusions : These results suggest that the actions of osteotropic hormones in bone metabolism may be partiallymediated by NO in the presence of cytokines.

방사선조사와 당뇨병이 백서 악하선의 caspase-3 발현에 미치는 영향

이흥기,황의환,이상래 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Purpose : To observe the histopathological changes and caspase-3 expression in the submandibular gland in streptozotocin-induced diabetic rats after irradiation. Materials and Methods : The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups: control, diabetes, irradiation, and diabetes-irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only. After 5 days, rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10 Gy to the head and neck region. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the submandibular gland were sectioned and observed using histopathological and immunohistochemical methods. Results : In the irradiation group, the condensed nucleus, karyolysis, and degeneration of the acinar cells and atrophy of the duct cells were observed in the early experimental phase. However, the acinar cells were found to be normal at 28 days after irradiation. In the diabetes group, the condensed nucleus, karyolysis, atrophy, and degeneration of the acinar cells were observed in the early experimental phase. However, the acinar cells were found to be normal at 21 days after diabetic state induction. In the diabetes-irradiation group, the ductal epithelial cells were predominant in their glandular tissues at 28 days after irradiation. In all of the experimental groups, the most prominent change of the acinar cells and ductal cells were observed at 14 days after diabetic state induction and irradiation. Conclusion : The expression of caspase-3 in the acinar cells and ductal cells of the submandibular gland was weak after irradiation, but that in the acinar cells, ductal cells, and fibrous cells of the submandibular gland was prominent after diabetic state induction.

괴사성 타액선화생 1증례 : 발병원인, 골변화, 발병율에 대한 고찰

이재서,강병철 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Necrotizing sialometaplasia (NS) is a rare, benign, self-limiting lesion, but it mimics carcinoma both clinically and histologically. Authors present a case of NS on the right posterior hard palate in a 16-year-old boy. This case showed underlying erosive bone change on CT images. We supposed this lesion resulted from the local anesthesia for dental treatment. Presented NS is the only one case from approximately 1,500 oral and maxillofacial biopsies (0.07%) at Chonnam National University Hospital during the period from 1999 to 2004.

하악에 전이된 위 선양암종

이지운,권기정,안현숙,고광준 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Metastatic tumors to the jaw bones are uncommon. The most common metastatic tumors to the jaw bones are the breast, lung and kidney. In the jaw bones, the common location of the lesions is the mandible, and the posterior area of the mandible is more commonly affected. The radiographic appearance is quite variable. In this report, a very rare case of metastatic gastric adenocarcinoma to the mandible is presented. The patient had undergone a gastrectomy 3 years ago.

방사선조사가 당뇨 백서의 치주조직에 미치는 영향

박동신,황의환,이상래 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Purpose : To observe the histopathological changes in the periodontal tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. Materials and Methods : The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups: control, diabetes, irradiation, and diabetes- irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. Results : In the diabetes group, osteoclastic activity was observed in the alveolar bone and the root throughout the period of experiment. Also, osteoblastic and fibroblastic activities were markedly decreased. In the irradiation group, the osteoclasts were observed in the alveolar bone and the dilated capillaries were increased in the early experimental phases. However, vigorous osteoblastic activity was noted in the late experimental phases. In the diabetes-irradiation group, osteoclastic activity in the alveolar bone and the root was observed in the early experimental phases. However, there were no resorption and osteoblastic activity in the alveolar bone and the root in the late experimental phases, and obvious atrophic change of fibrous tissues was noted. Conclusion : This experiment suggests that osteoblastic activity was caused by irradiation in the late experimental phases, but atrophic change of the periodontal ligament tissues was induced after irradiation in diabetic state.

치과 방사선 촬영기의 표면선량 변화

이재서,강병철,윤숙자 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.2

Purpose : The purpose of this study was to investigate variability of doses with same exposure parameters and evaluate radiographic density according to the variability of doses. Materials and methods : Twenty-eight MAX-GLS (Shinhung Co, Seoul, Korea), twenty-one D-60-S (DongSeo Med, Seoul, Korea), and eleven REX-601 (Yoshida Dental MFG, Tokyo, Japan) dental x-ray machines were selected for this study. Surface doses were measured under selected combinations of tube voltage, tube current, exposure time, and constant distance 42 cm from the focal spot to the surface of the Multi-O-meter (Unfors Instruments, Billdal, Sweden). Radiographic densities were measured on the films at maximum, minimum and mean surface doses of each brand of x-ray units. Results : With MAX-GLS, the maximum surface doses were thirteen to fourteen times as much as the minimum surface doses. With D-60-S, the maximum surface doses were three to eight times as much as the minimum surface doses. With REX-601, the maximum surface doses were six to ten times as much as the minimum surface doses. The differences in radiographic densities among maximum, mean, and minimum doses were significant (p<0.01). Conclusion : The surface exposure doses of each x-ray machine at the same exposure parameters were different within the same manufacturer’s machines.

측두하악관절 내장증 환자의 임상증상과 자기공명영상 소견의 비교 연구

권기정 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.2

Purpose : To determine the clinical correlation of magnetic resonance imaging (MRI) findings of temporomandibular joint internal derangements. Materials and Methods : The MR images of 150 TMJs in 75 patients were analyzed. The clinical symptoms were pain in the preauricular area and masticatory muscles and TMJ sounds. Results : There was a statistically significant relationship between the MRI diagnoses of different types of disc displacements and clinical findings of pain, clicking, and crepitus. The risk of TMJ pain was increased when the disc displacement without reduction occurred at the same time in combination with the osteoarthrosis and effusion. Conclusion : Regardless of the results, the data indicate that each of these MR imaging variables may not be regarded as the unique and dominant factor in defining TMJ pain occurrence.

프랙탈 분석을 통한 임플란트 주변골 평가

정연화 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Purpose : The purpose of this study was to investigate whether the fractal dimension of successive panoramic radiographs of bone after implant placement is useful in the characterization of structural change in alveolar bone. Materials and Methods : Twelve subjects with thirty-five implants were retrospectively followed-up from one week to six months after implantation. Thirty-six panoramic radiographs from twelve patients were classified into 1 week, 1-2 months and 3-6 months after implantation and digitized. The windows of bone apical and mesial or distal to the implant were defined as periapical region of interest (ROI) and interdental ROI; the fractal dimension of the image was calculated. Results : There was not a statistically significant difference in fractal dimensions during the period up to 6 months after implantation. The fractal dimensions were higher in 13 and 15 mm than 10 and 11.5 mm implant length at interdental ROIs in 3-6 months after implantation (P<0.01). Conclusion : Longer fixtures showed the higher fractal dimension of bone around implant. This investigation needs further exploration with large numbers of implants for longer follow-up periods.