• Imaging Science in Dentistry
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• v.39 no.4
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• pp.199-203
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• 2009

Purpose : To measure dose-width product (DWP) values used for dental panoramic radiography in Anyang city, Korea. Materials and Methods : Thirty-six panoramic dental radiographic sets (17 analogue panoramic sets and 19 digital panoramic sets) in 36 dental clinics in Anyang city were included in the study. Each patient's panoramic exposure parameters were simulated and the panoramic radiation doses were measured at the secondary collimator using a Mult-O-Meter (Unfors Instruments, Billdal, Sweden) at each dental clinic during 2006. The third quartile DWP was determined from 310 surface dose measurements on adult. Results : The third quartile DWP for adult panoramic radiograph was 106.7 mGy mm. For analogue and digital panoramic radiograph, 3/4 DWP were 116.8 mGy mm and 72 mGy mm respectively. The overall third quartile DWP of panoramic radiography was 106.7 mGy mm. Conclusion : The measured 3/4 DWPs were higher than the 3/4 DWP of 65 mGy mm recommended by NRPB. Dentists who are operating above the reference dose should lower their panoramic exposure doses below the recommended reference value by changing the exposure parameters and/or their panoramic equipments.

• Imaging Science in Dentistry
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• v.30 no.1
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• pp.49-54
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• 2000

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 periapical radiographs. Radiographs were assessed for the presence of interproximal caries by three oral and maxillofacial radiologists independantly. 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.

• Journal of information and communication convergence engineering
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• v.17 no.4
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• pp.274-278
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• 2019

It is important that students are provided opportunities to practice their skills in acquiring radiographic images. However, these opportunities are currently limited because of the risk of radiation exposure. To overcome this limitation, a new augmented reality-based radiography simulator was developed that enables students to practice radiographic techniques as part of self-directed learning without time and space constraints. Subsequently, cross-sectional images of a manikin phantom head obtained via computed tomography were reconstructed into a three-dimensional object. An image marker that could be recognized by a mobile device and could allow users to practice dental radiography techniques was devised. The three-dimensional object was augmented to the mobile device; consequently, among 106 stored dental radiographs on the device, a radiograph corresponding to specific imaging conditions was opened when users performed radiographic procedures. This technology could improve dental students' understanding of dental anatomy and contribute to improving their competency in acquiring dental radiographs.

• Imaging Science in Dentistry
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• v.35 no.1
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• pp.15-23
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• 2005

Purpose : To compare cephalometric measurement between measuring methods in digital and conventional lateral cephalometric radiograph. Materials and Methods : Twenty digital and conventional lateral cephalometric radiographs were selected. In digital group, cephalometric measurements were performed manually using hardcopies and automatically using $V-Ceph^{TM}$ program on the monitor. In conventional group, the same measurements were performed manually on conventional films, and for automatic measurement conventional films were digitized by scanner. All measurements were performed twice by 4 observers, and 24 cephalometric variables were calculated and the time spent for each measurement was recorded. The differences in measurements data and the time spent for each measurement were compared within each group. Intra-observer and inter-observer comparisons were performed. Results : In both groups, no statistically significant difference between manual and automatic measurements was observed and most of the variables didn't show statistically significant differences between methods. The observer with less experience tended to show statistically significant differences of measurements between methods, and differences from other observers. The differences of measurements between methods in digital group were lesser than those of conventional group with statistical significance in 8 variables out of 24. With automatic method and in digital group, the spent time was shorter. Conclusion : With direct digital radiograph, automatic method using manually idenitified landmarks can be preferable in cephalometric analysis. (Korean J Oral Maxillofac Radiol 2005; 35 : 15-23)

• Imaging Science in Dentistry
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• v.40 no.1
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• pp.25-32
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• 2010

Purpose : This study was designed to evaluate the efficacy and utility of panoramic radiograph for the improvement of the periodic oral examinations. Materials and Methods : Clinical examinations and panoramic examinations were done for the 242 subjects of oral examinations. The results of panoramic radiograph interpretation were compared with the clinical findings. Two questionnaires were created. One was carried out before the panoramic examination and the other done afterwards, to find out the subjects' cognition and satisfaction for the clinical and panoramic examinations. Results : 1. Panoramic findings showed a higher detection rate of 31.9% for periodontal diseases, and 23.1% for dental caries than clinical findings. 2. The additional abnormalities detected through panoramic examinations were impacted tooth in 81 subjects (33.6%), maxillary sinus abnormalities in 28 subjects (11.6%), condylar abnormalities in 5 subjects (2.1%), congenital and acquired dental anormalies in 59 subjects (24.5%), and other miscellaneous abnormalities in 34 subjects (14.1%). 3. 164 subjects (67.8%) were satisfied with the current periodic oral examination, and 75 subjects (31.1%) hoped for better accuracy. 4. In the first and second questionnaire, 154 subjects (67.0%) and 163 subjects (70.6%) responded respectively that panoramic examination was necessary, and 193 subjects (83.2%) responded that it actually helped. Conclusion : The panoramic examination was revealed to improve the effectiveness of the periodic oral examination and to increase the satisfaction of the subjects of examination.

• Imaging Science in Dentistry
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• v.41 no.4
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• pp.155-159
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• 2011

Purpose : This study was performed to determine the prevalence of maxillary canine impaction on a basis of a single panoramic radiograph in Bangladeshi population. Materials and Methods : A random sample of seven hundred panoramic radiographs was collected from the patient record of a dental clinic. All the selected panoramic radiographs were taken from January 2009 to August 2010 by a single panoramic radiograph machine with the same exposure time (19 seconds) for all radiographs. One hundred and twenty panoramic radiographs were excluded to minimize the selection bias. In a dim lit room, an observer assessed the radiographs on a standard radiographic light box. The position of the impacted maxillary canine was recorded in line with the longitudinal axis of a tooth using the edge of a metal ruler. Data were subsequently put on SPSS 11.5 software and chi-square (${\chi}^2$) tests were applied to find out the association. Results : Among 580 panoramic radiographs it was found that impacted maxillary canines were present in only 7 (1.2%) radiographs. A statistical significant difference was found between the age of the patients and the vertical position of the impacted canines (p=0.000) and between the age of the patients and the horizontal position of the impacted canines (p=0.003). Conclusion : The prevalence was found to be low compared with the present study from the limitation of panoramic image. Further study needs to include three-dimensional imaging modality.

• Journal of Trauma and Injury
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• v.25 no.3
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• pp.97-100
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• 2012

We report a case of delayed diagnosed pneumonia due to an aspirated metallic crown, which had been detached from a molar tooth. Dental prosthesis should be checked and a careful review of the chest radiograph is mandatory when an elderly patient with delirium after hip fracture surgery develops pneumonia postoperatively.

• The Journal of the Korean dental association
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• v.20 no.12 s.163
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• pp.1025-1028
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• 1982

1) The authors have had a case of crown fractured upper central incisor with open apex and non vital pulp. 2) The patient was 8 years old female. 3) Apical closure has been induced with the use of calcium hydroxide and gutta percha cone. 4) At nine month after filling with calcium hydroxide and gutta percha cone, apical closure was observed by radiograph. 5) Root canal was permanently filled gutta percha cone and zinc oxide eugenol by the lateral condensation technique.

• The Journal of the Korean dental association
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• v.13 no.3
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• pp.231-234
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• 1975

The true cementoma (attached cementoma) is an unusual benign jaw neoplasm fused to the root of the involved tooth. The authors have treated a true cementoma occurs at the right mandibular first molar. The 26 years old male patient who has complained of sweeling and discomfort of the involved tooth. The radiograph showed that the tumor represents a dense radiopacity bordered by a well demarcated peripheral radiolucent zone. Treatment was performed by extraction of the involved tooth with complete enucleation of the tumor. So the operation was done without any complications.

• The Journal of the Korean dental association
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• v.5 no.1
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• pp.56-59
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• 1964

The authors have observed a case of giant-cell reparative granuloma which were occurred in the mandible of 30 year old man . 1.The lesion of accompanying inflammation was lacated at the anterior portion of the mandible. 2.Radiograph shows ovoid radiolucent shadow with irregular margin. 3. Microscopic section reveals granulation tissue and many multinucleated gaint cells exist adjacent to the hemorrhagic areas.