• Imaging Science in Dentistry
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• v.47 no.1
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• pp.11-15
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• 2017

Purpose: This study was performed to investigate the intra- and inter-observer variability in linear measurements with axial images obtained by PreXion (PreXion Inc., San Mateo, USA) and i-CAT(Imaging Sciences International, Xoran Technologies Inc., Hatfield, USA) CBCT scanners, with different voxel sizes. Materials and Methods: A cylindrical object made from nylon with radiopaque markers (phantom) was scanned by i-CAT and PreXion 3D devices. For each axial image, measurements were taken twice in the horizontal(distance A-B) and vertical (distance C-D) directions, randomly, with a one-week interval between measurements, by four oral radiologists with five years or more experience in the use of these measuring tools. Results: All of the obtained linear measurements had lower values than those of the phantom. The statistical analysis showed high intra- and inter-observer reliability (p=0.297). Compared to the real measurements, the measurements obtained using the i-CAT device and PreXion tomography, on average, revealed absolute errors ranging from 0.22 to 0.59 mm and from 0.23 to 0.63 mm, respectively. Conclusion: It can be concluded that both scanners are accurate, although the linear measurements are underestimations, with no significant differences between the evaluators.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.48-48
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• 2006

• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.205-214
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• 2016

Objectives: The purpose of the study is to investigate the current status and radiographic safety management in Korea. Methods: A self-reported questionnaire was completed by 200 dental hygienists in Jeonbuk province from September 1, 2014 and October 31, 2014. The questionnaire consisted of general characteristics of the subjects, radiation knowledge, radiation safety management, and radiation exposure anxiety. Data were analyzed using SPSS 18.0 program. Results: Duration of clinical experience(r=0.142) and number of daily radiation shot(r=0.145) showed a positive correlation to radiation safety management, and a nrgative correlation to use of intraoral films and digital devices(r=-0.587). A logistic regression analysis was performed in order to evaluate the influence on radiography knowledge. The results showed that the factors had significant influences on the age group over 41 years old(OR 7.25; 95% CI 1.30-40.43) and those who took a position above team leader(OR 0.23; 95% CI 0.59-0.90). Conclusions: It is very important to have the safety management toward dental intraoral imaging and radiograpgic shot in the dental hygienists. Continuous efforts should be emphasized on radiographic safety management and behavior.

• The Journal of the Korean dental association
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• v.55 no.11
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• pp.800-807
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• 2017

Ultrasonography is one of the most common diagnostic tools in medical imaging with non-invasive and non-radiation loaded characteristics. In the field of dentistry, especially for periodontology, high frequency ultrasonic device can be used for several purposes such as evaluating gingival thickness, identifying the level of alveolar bone, measuring the volume of mucosa of donor site for soft tissue graft and so on. According to recent studies, it was demonstrated that ultrasonic diagnosis had both accuracy and repeatability comparable to conventional diagnostic tools. However, improvement and development of intra-oral probe suitable for adpatation to gingiva and palatal mucosa, are considered as prerequisites for diffusion of ultrasonic diagnosis in periodontology.

• Progress in Medical Physics
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• v.26 no.1
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• pp.52-58
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• 2015

The automated dental cavity detection program for a new concept intra-oral dental x-ray imaging device, an auxiliary diagnosis system, which is able to assist a dentist to identify dental caries in an early stage and to make an accurate diagnosis, was to be developed. The primary theory of the automatic dental cavity detection program is divided into two algorithms; one is an image segmentation skill to discriminate between a dental cavity and a normal tooth and the other is a computational method to analyze feature of an tooth image and take an advantage of it for detection of dental cavities. In the present study, it is, first, evaluated how accurately the DRLSE (Direct Regularized Level Set Evolution) method extracts demarcation surrounding the dental cavity. In order to evaluate the ability of the developed algorithm to automatically detect dental cavities, 7 tooth phantoms from incisor to molar were fabricated which contained a various form of cavities. Then, dental cavities in the tooth phantom images were analyzed with the developed algorithm. Except for two cavities whose contours were identified partially, the contours of 12 cavities were correctly discriminated by the automated dental caries detection program, which, consequently, proved the practical feasibility of the automatic dental lesion detection algorithm. However, an efficient and enhanced algorithm is required for its application to the actual dental diagnosis since shapes or conditions of the dental caries are different between individuals and complicated. In the future, the automatic dental cavity detection system will be improved adding pattern recognition or machine learning based algorithm which can deal with information of tooth status.