• The Journal of the Korean dental association
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• v.54 no.9
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• pp.712-728
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• 2016

These days, the clinical course of dental imaging sector has done a lot of implant-related imaging courses, including cone beam CT. In contrast, the general image reading course is not given a lot of opportunities to learn. Therefore, it is imperative that we talk about the general image interpretation that can be read easily applied in a dental clinic. When we see a strange radiographic finding of our patient in the dental clinic, we should first check whether the radiographic finding is a normal finding or a morbidity. If the finding is diagnosed as a morbidity, you should make plans for the appropriate therapy. The most important step is classification between normal state and morbidity. Some lesions may occur without any clinical symptoms. Therefore, we should read all the parts of radiographs, even the patient does not have clinical symptoms.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.333-336
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• 2021

Rhinoliths are foreign bodies composed of mineralised deposits in the nasal cavity that are rarely encountered in routine dental practice. The current report presents a case of a 77-year-old female patient who visited a dental treatment centre for a routine dental check-up and prophylaxis. On the clinical examination, the patient did not report any breathing difficulty, nasal obstruction, or any form of discharge. Panoramic radiography showed a horizontally magnified radiopaque structure in the right nasal fossa region. Cone-beam computed tomography (CBCT) revealed a hyperdense entity with a laminated presentation in the right nasal fossa. The hyperdense entity was diagnosed as a rhinolith based on the radiographic findings. Although the patient was asymptomatic, a referral was made to an ear, nose, and throat surgeon for a further evaluation. This report highlights the importance of CBCT imaging in the diagnosis of soft-tissue calcifications.

• Imaging Science in Dentistry
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• v.42 no.2
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• pp.65-70
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• 2012

Purpose : The aim of this study was to compare the effective dose for imaging of mandible between multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). An MDCT with low dose technique was also compared with them. Materials and Methods : Thermoluminescent dosimeter (TLD) chips were placed at 25 organ sites of an anthropomorphic phantom. The mandible of the phantom was exposed using 2 different types of MDCT units (Somatom Sensation 10 for standard-dose MDCT, Somatom Emotion 6 for low-dose MDCT) and 3 different CBCT units (AZ3000CT, Implagraphy, and Kavo 3D eXaM). The radiation absorbed dose was measured and the effective dose was calculated according to the ICRP 2007 report. Results : The effective dose was the highest for Somatom Sensation 10 (425.84 ${\mu}Sv$), followed by AZ3000CT (332.4 ${\mu}Sv$), Somatom Emotion 6 (199.38 ${\mu}Sv$), and 3D eXaM (111.6 ${\mu}Sv$); it was the lowest for Implagraphy (83.09 ${\mu}Sv$). The CBCT showed significant variation in dose level with different device. Conclusion : The effective doses of MDCTs were not significantly different from those of CBCTs for imaging of mandible. The effective dose of MDCT could be markedly decreased by using the low-dose technique.

• Journal of radiological science and technology
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• v.44 no.3
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• pp.195-203
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• 2021

Although intra oral dental x-ray is a lower dose than other radiological examinations, pediatric patients are known to have a higher risk of radiation damage than adults. For this reason, pediatric dental x-ray requires management of dose evaluation and imaging conditions during the examination. In this study, the dose calculation program ALARA-Dental(child/adult) was used to evaluate the organ dose and effective dose exposed to each examination site during intra oral imaging of children during dental radiographic examination, and dose analysis according to the imaging conditions was performed. As a result, the highest organ dose distribution was shown at 0.044 ~ 0.097 mGy in all are as of the mucous membrane of oral cavity except for the maxillary incisors and canines. Also, in the case of the thyroid gland, the maxillary canine and maxillary premolar examination showed 0.027 and 0.020 mGy, respectively, and the dose distribution was 15.4% to 70.0% higher than that of the mandibular examination. As for the effective dose calculated during intra oral imaging, the maxillary anterior and canine examinations showed the highest effective doses of 0.005 and 0.004 mSv, respectively, and the maxillary area examination showed a higher dose distribution on average than the mandible.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.149-159
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• 1999

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.

• Imaging Science in Dentistry
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• v.33 no.4
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• pp.239-244
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• 2003

Malignant fibrous histiocytoma (MFH) is a pleomorphic soft tissue sarcoma. Three cases of MFH were reported in our study. The first case involved in the right infratemporal fossa of a 32-year-old female was presented. MR imaging revealed a 5.0 × 3.3 cm soft tissue mass of inhomogeneous high signal intensity. The second case was found in the right hard palate of a 66-year-old male. CT demonstrated bone destruction and MR imaging showed a 4 × 4 cm sized soft tissue mass of heterogeneous high signal intensity. The final case was found in the left masticator space of a 37-year-old male. The CT image showed a large mass with massive bone destruction of the left mandibular ramus, while the MRI displayed a soft tissue mass, 8 cm diameter. Our cases exhibited the general features of MFH. MRI is essential in the imaging of MFH, namely to depict tumor borders and demonstrate relationships with adjacent structures.

• Imaging Science in Dentistry
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• v.45 no.3
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• pp.181-185
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• 2015

Numerous cases of enamel renal syndrome have been previously reported. Various terms, such as enamel renal syndrome, amelogenesis imperfecta and gingival fibromatosis syndrome, and enamel-renal-gingival syndrome, have been used for patients presenting with the dental phenotype characteristic of this condition, nephrocalcinosis or nephrolithiasis, and gingival findings. This report describes a case of amelogenesis imperfecta of the enamel agenesis variety with nephrolithiasis in a 21-year-old male patient who complained of small teeth. The imaging modalities employed were conventional radiography, cone-beam computed tomography, and renal sonography. Such cases are first encountered by dentists, as other organ or metabolic diseases are generally hidden. Hence, cases of amelogenesis imperfecta should be subjected to advanced diagnostic modalities, incorporating both dental and medical criteria, in order to facilitate comprehensive long-term management.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.177-183
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• 2014

Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of periradicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

• Imaging Science in Dentistry
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• v.54 no.1
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• pp.115-120
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• 2024

Components derived from an infected lesion within the bone can spread through various passages in the mandible, particularly via the mental foramen. Radiologically, the spread of infection is typically nonspecific and challenging to characterize; however, multislice computed tomography (MSCT) can effectively detect pathological changes in soft tissues and the bone marrow space. This report describes the case of a 55-year-old woman who experienced mental nerve paresthesia due to a periapical infection of the right mandibular second premolar. MSCT imaging revealed increased attenuation around the periapical lesion extending into the mandibular canal and loss of the juxta-mental foraminal fat pad. Following endodontic treatment of the tooth suspected to be the source of the infection, the patient's symptoms resolved, and the previous MSCT imaging findings were no longer present. Increased bone marrow attenuation and obliteration of the fat plane in the buccal aspect of the mental foramen may serve as radiologic indicators of inflammation spreading from the bone marrow space.

• Imaging Science in Dentistry
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• v.33 no.1
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• pp.27-33
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• 2003

Purpose : The purpose of this experiment was to evaluate the diagnostic ability of a CCD-based digital system (CDX-2000HQ) in the detection of incipient dental caries. Materials and Methods : 93 extracted human teeth with sound proximal surfaces and interproximal artificial cavities were radiographed using 4 imaging methods. Automatically processed No.2 Insight film (Eastman Kodak Co., U.S.A.) was used for conventional radiography, scanned images of conventional radiograms for indirect digital radiography were used. For the direct digital radiography, the CDX-2000HQ CCD system (Biomedisys Co. Korea) was used. The subtraction images were made from two direct digital images by Sunny program in the CDX-2000HQ system. Two radiologists and three endodontists examined the presence of lesions using a five-point confidence scale and compared the diagnostic ability by ROC (Receiver Operating Characteristic) analysis and one way ANOV A test. Results: The mean ROC areas of conventional radiography, indirect digital radiography, direct digital radiography, and digital subtraction radiography were 0.9093, 0.9102, 0.9184, and 0.9056, respectively. The diagnostic ability of direct digital radiography was better than the other imaging modalities, but there were no statistical differences among these imaging modalities (p > 0.05). Coclusion : These results indicate that new CCD-based digital systems (CDX-2000HQ) have the potential to serve as an alternative to conventional radiography in the detection of incipient dental caries.