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)

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)

의원성 사고로 발생한 타액선염 : 증례보고

김현우,허경회,이원진,허민석,이삼선,최순철 대한구강악안면방사선학회 2004 Imaging Science in Dentistry Vol.34 No.2

A case of sialadenitis is presented in a patient with painful swelling of the right mouth floor. The condition was caused by trauma on the right mouth floor during dental treatment, which had happened 15 days before admission. On aspiration, mucous secretion was found and ultrasonography showed obstruction of duct. Histopathological studies and surgical investigation established a definite diagnosis of obstructive sialadenitis caused by ductal laceration. As surgical treatment sialodochoplasty was selected. The case and relevant considerations are discussed.

하치조신경을 포함하는 발육성 타액선골결손

한진우,최항문 대한구강악안면방사선학회 2004 Imaging Science in Dentistry Vol.34 No.3

The present study reports a case of developmental salivary gland defect. On panoramic examination, large radiolucent lesion surrounded by a sclerotic wall was noted in the right posterior mandible. On CT examination, large lingual bone concavity with extra-osseous course of the inferior alveolar nerve bundle was detected. In atypical cases, it is suggested that confirmatory imaging using CT or MRI should be taken.

저선량 방사선이 MC3T3-E1 골모세포주의 석회화결절 형성에 미치는 영향

김경아,고광준 대한구강악안면방사선학회 2004 Imaging Science in Dentistry Vol.34 No.3

Purpose : To investigate the effects of low dose irradiation on the calcium content and calcific nodule formation of the MC3T3-E1 osteoblastic cell line. Materials and Methods : Cells were irradiated with a single dose of 0.2, 0.4 and 0.6 Gy at a dose rate of 5.38 Gy/min using Cs-137 irradiator. After irradiation, the calcium content and calcific nodule formation were examined on the 1st, 2nd, 3rd and 4th week. Results : We did not find any significant difference of total calcium content after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group. There was no significant difference of total calcium content between 0.2, 0.4 and 0.6 Gy irradiated groups. We found an increased tendency of the calcific nodule formation after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group without significant difference of calcific nodule formation between 0.2, 0.4 and 0.6 Gy irradiated groups. Conclusion : The results showed an increased tendency of the calcific nodule formation after low dose irradiation. However, this tendency did not increase with the increase of irradiation dose.

Current status and installation standard of dental PACS

Park, Chang-Seo,Kim, Kee-Deog,Park, Hyok,Jeong, Ho-Gul 대한구강악안면방사선학회 2004 Imaging Science in Dentistry Vol.34 No.4

Purpose : Picture Archiving and Communication System (PACS) is difficult to implement in the best of situations,but evidence is growing that the benefits are significant. The aims of this study are to analyze the current status of full PACS and establish successful installation standard of dental PACS. Materials and Methods : Materials and methods were based on the investigation of current working status and installation standard of PACS, and observation of variable issues to installation of dental PACS. Results : By September 30, 2004, full PACS implementations in their facilities were 88.1% in specialized general hospitals (37 installations out of total 42 hospitals), 59.8% in general hospitals (144 installations out of total 241 hospitals), 12.3% in medical hospitals (116 installations out of total 941 hospitals) and 3.6% in dental hospitals (4 installations out of total 110 hospitals) Only 4 university dental hospitals currently have installed and are operating full PACS. Major obstacle to wide spread of dental PACS is initial high investments. Conclusions : Clinical environments of dental PACS differed from medical situation. Because of characteristic dental practice, the initial investments for dental PACS are generally much greater than those of medical PACS.Also new economic crisis makes users scruple. The best way to overcome these limitations is to establish an economic installation standard for dental PACS. Also the clear technical communication between the customer and the supplier before both sides are committed to the obstacles are critical to its success

6세 아동을 위한 파노라마방사선사진 상층의 연구

김상연,최항문,한진우,이설미 대한구강악안면방사선학회 2004 Imaging Science in Dentistry Vol.34 No.2

Purpose : To make a focal trough (image layer) for an average maxillary dental arch of 6-year-old korean in panoramic radiography. Materials and Methods : Phantom for the maxillary dental arch was designed using intercanine width, intermolar width, tooth size, and interdental spacing to record the data of 6-year-old child. The characteristics of pre-corrected panoramic machine (for adult) was evaluated using the phantom, resolution test pattern for margin of the image layer, and metal ball for the center of the image layer. Panoramic image layer of the child was developed by means of decreasing the speed of film-cassette and positioning the phantom backwards, and then the characteristics of post-corrected panoramic machine (for child) were reevaluated. Results : At post-corrected panoramic image layer, beam projection angles at all interdental areas increased for about 2.6-3.8.., the position of the image layer was shifted toward the rotation center for about 2.5 mm at the deciduous central incisior area. The width of image layer decreased at all areas. Conclusion : Increased beam projection angle will reduce the disadvantage of tooth overlap, and the same form between the center of the image layer and dental arch will improve image resolution.

Diagnostic accuracy of artificially induced vertical root fractures : a comparison of direct digital periapical images with conventional periapical images

Lee, Ji-Un,Kwon, Ki-Jeong,Koh, Kwang-Joon 대한구강악안면방사선학회 2004 Imaging Science in Dentistry Vol.34 No.4

Purpose : To compare the diagnostic accuracy for the detection of root fractures in CMOS-based digital periapical images with conventional film-base periapical images. Materials and Methods : Sixty extracted single-root human teeth with closed apices were prepared endodontically and divided into two groups; artificially induced vertical root fracture group and control group. All radiographs were obtained using the paralleling technique. The radiographs were examined by 4 observers three times within a 4 week interval. Receiver operating characteristic (ROC) analysis was carried out using data obtained from four observers. Intra- and inter-examiner agreements were computed using kappa analysis. Results : The area under the ROC curve (Az) was used as an indicator of the diagnostic accuracy of the imaging system. Az values were as follows: direct-digital images; 0.93, film-based images; 0.92, and inverted digital images; 0.91. There was no significant difference between imaging modalities (P<0.05). The kappa value of interobserver agreement was 0.42 (range: 0.28-0.60) and intra-observer agreement was 0.57 (range: 0.44-0.75). Conclusion : There is no statistical difference in diagnostic accuracy for the detection of vertical root fractures between digital periapical images and conventional periapical images. The results indicate that the CMOS sensor is a good image detector for the evaluation of vertical root fractures.

나선형 단층방사선사진촬영에서 하악골 위치가 측정치에 미치는 영향

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

Purpose : To evaluate the effect of deviation of mandibular positioning, by changing the mandibular plane inclination, on the measured height and width of mandible in spiral conventional tomography. Materials and Methods : By means of the Scanora multifunctional unit, cross-sectional tomograms were taken from two human dried mandibles at the mandibular angulations: -15 degree, -10 degree, -5 degree, and 0 degree. Twenty-eight sites in two dried mandibles were imaged. One examiner measured the bone heights and widths at selected sites on the images and the actual bone heights were recorded. Results : The bone heights at the four mandibular inclinations overestimated real bone heights and the mean difference between actual heights and image heights on 0 degrees was the smallest (P/0.01). The bone widths on -15 degrees were narrowest and there were significant differences between bone widths measured at the four mandibular inclinations (P/0.001). We found statistically significant differences between both bone heights and widths as measured according to the mandibular plane angle for the posterior region (P 0.01). Conclusion : The use of different mandibular positioning may result in discrepancies in heights and widths when measured from the cross-sectional tomographic images. It is suggested that the mandibular positioning may play a significant role in the measurement of mandibular heights and widths.

전산화 단층촬영을 이용한 법랑모세포종의 방사선학적 연구

박혁,정호걸,김기덕,박창서 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.2

Purpose : To reveal what is the distinct differential diagnostic differences between unicystic ameloblastoma and solid or multicystic ameloblastoma. Materials and Methods : 56 cases of ameloblastoma were retrospectively reviewed and evaluated among the patients who had taken CT scans at the department of Oral & Maxillofacial Radiology in Yonsei University Dental Hospital from January 1996 to December 2003. Results : In 56 cases, 21 cases (37.5%) were unicystic ameloblastoma, 35 cases (62.5%) were solid or multicystic ameloblastoma. Only 1 case (4.8%) of unicystic ameloblastoma and 4 cases (11.4%) of solid or multicystic ameloblastoma were occurred in maxilla. 13 cases (61.9%) of unicystic ameloblastoma were observed as unilocular, and 8 cases (38.1%) as lobulated. 5 cases (14.3%) of solid or multicystic ameloblastoma were observed as unilocular, 13 cases (37.1%) as lobulated, and 17 cases (48.6%) as multilocular. In the results from the measurements after correction of the buccolingual widths and heights to the mesiodistal lengths, there is a statistically significant difference between unicystic ameloblastoma and solid or multicystic ameloblastoma in ANCOVA test (p<0.05). Hounsfield units in the lesion were 24.9±8.8 HU in unicystic ameloblastoma, 31.2±11.5 HU in solid or multicystic ameloblastoma. There is no statistically significant difference (p>0.05). Conclusion : Characteristic differences between unicystic ameloblastoma and solid or multicystic ameloblastoma is that there is higher prevalence of solid or multicystic ameloblastoma that have lobulated or multilocular patterns. To measure the Hounsfield units in the lesion is helpful, but it is not a differential diagnostic point between unicystic ameloblastoma and solid or multicystic ameloblastoma.