• Journal of dental hygiene science
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• v.22 no.2
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• pp.75-82
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• 2022

Background: Dental hygienists study dental radiology through the dental hygiene department and curriculum, and most of the radiography work in dental clinics is performed by dental hygienists; however, the legal work regulations for dental hygienists place restrictions on the type of radiography performed. This study aimed to identify the actual conditions of the radiographic work performed by dental hygienists and to determine the difference according to the type of hospital. Methods: This study included 195 dental hygienists working at dental medical institutions in the metropolitan area. A survey was conducted on regarding the radiographic work performed and the clinical career of the main performers. The radiography work was divided into periapical radiography, bite-wing radiography, occlusal radiography, panoramic radiography, computed tomography (CT), and cephalometric radiography. Results: The frequency of performing intraoral radiography was as follows: periapical radiography, 94.9%; bite-wing radiography, 93.8%; and occlusal radiography, 77.9%. The frequency of performing extraoral radiography was 94.4% for panoramic radiography, 89.7% for CT, and 73.3% for cephalometric radiography. The frequency of internal and external radiography performance was higher among hygienists in dental clinics than among those in dental hospitals and university hospitals. The analysis of the dental hygienists' clinical experience in the areas of intraoral and extraoral radiography showed that those working at university hospitals, dental hospitals, and dental clinics had over 5 years, 2~4 years, and 1 year of clinical experience, respectively. The hygienists with less than 1 year of clinical experience showed high performance frequency (p<0.05). Conclusion: For the dental hygienists to perform radiography safely, a discussion regarding the revision of related laws and regulations is warranted.

• Imaging Science in Dentistry
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• v.31 no.1
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• pp.51-55
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• 2001

Purpose : This study was performed to compare the diagnostic ability of conventional intraoral radiographs with that of digital subtraction image and to assess the quantifying ability of digital subtraction image for simulated apical root resorption Materials and Methods : Conventional intraoral radiographs and digital images of ten sound maxillary central incisors and those with simulated apical root resorption were taken with varying horizontal and vertical angulations of the x-ray beam. The diagnostic accuracy to detect the lesion was evaluated on conventional intraoral radiographs and digital subtraction images by ROC analysis. The amount of simulated apical root resorption was also estimated on the reconstruction images by Emago/sup (R)/ and compared with actual amount of tooth loss using paired t-test. Results: The diagnostic accuracy of conventional intraoral radiographs to detect the apical root resorption was low (ROC area = 0.6446), and the sensitivity and the specificity of digital subtraction images were 100%, respectively. The calculated amounts of apical root resorption showed no statistically significant difference with the actual amounts of the lesion (p>0.05). Conclusion: Digital subtraction radiography is powerful tool to detect the small apical root resorption, and quantitative analysis of small amounts of the lesion can be evaluated by digital subtraction radiography.

• Imaging Science in Dentistry
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• v.37 no.3
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• pp.149-156
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• 2007

Purpose: The purpose of this study was to measure the absorbed dose and to calculate the effective dose for periapical radiography done by portable intraoral x-ray machines. Materials and Methods: 14 full mouth, upper posterior and lower posterior periapical radiographs were taken by wall-type 1 and portable type 3 intraoral x-ray machines. Thermoluminescent dosemeters were placed at 23 sites at the layers of the tissue-equivalent ART woman phantom for dosimetry. Average tissue absorbed dose and radiation weighted dose were calculated for each major anatomical site. Effective dose was calculated using 2005 ICRP tissue weighted factors. Results: On 14 full mouth periapical radiographs, the effective dose for wall-type x-ray machine was 30 Sv; for portable x-ray machines were 30 Sv, 22 Sv, 36 Sv. On upper posterior radiograph, the effective dose for wall-type x-ray machine was 4 Sv; for portable x-ray machines doses were 4 Sv, 3 Sv, 5 Sv. On lower posterior radiograph, the effective dose for wall type x-ray machine was 5 Sv; for portable x-ray machines doses were 4 Sv, 4 Sv, 5 Sv. Conclusion: Effective doses for periapical radiographs performed by portable intraoral x-ray machines were similar to doses for periapical radiographs taken by wall type intraoral x-ray machines.

• Imaging Science in Dentistry
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• v.33 no.3
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• pp.131-135
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• 2003

Purpose: To determine whether the mandibular radiomorphometric indices in panoramic radiography are correlated with the bone mineral density of Cu-equivalent images in intraoral film. Materials and Methods: The bone mineral density (BMD) of the mandibular premolar area was measured in the Cu-equivalent image of intraoral film. The Panoramic Mandibular Index (PMI) and Mandibular Cortical Width (MCW) were measured in panoramic radiographs of six dry mandibles, and the Pearson correlation between PMI, MCW, and BMD were tested. Results: There were no significant correlations between PMI and BMD (r = 0.280), nor between MCW and BMD (r =0.237). Conclusion: The results show that PMI and MCW were poor diagnostic indicators of mandibular BMD in the six dry mandibles used in this study. The correlationship between the mandibular radiomorphometric indices (PMI and MCW) and mandibular BMD needs to be researched further using large in vivo patient samples.

• Imaging Science in Dentistry
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• v.49 no.3
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• pp.219-228
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• 2019

Purpose: The aim of this study was to determine the reasons and solutions for intraoral phosphor storage plate (PSP) image artifacts and errors, and to develop an appropriate classification of the artifacts. Materials and Methods: This study involved the retrospective examination of 5,000 intraoral images that had been obtained using a phosphor plate system. Image artifacts were examined on the radiographs and classified according to possible causative factors. Results: Artifacts were observed in 1,822 of the 5,000 images. After examination of the images, the errors were divided into 6 groups based on their causes, as follows: images with operator errors, superposition of undesirable structures, ambient light errors, plate artifacts (physical deformations and contamination), scanner artifacts, and software artifacts. The groups were then re-examined and divided into 45 subheadings. Conclusion: Identification of image artifacts can help to improve the quality of the radiographic image and control the radiation dose. Knowledge of the basic physics and technology of PSP systems could aid to reduce the need for repeated radiography.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.2
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• pp.415-423
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• 1991

This study was performed to evaluate the geometric standardization of periapical intraoral radiography. Image distortion was measured by analysing serial radiography obtained from dry skull using 5 types of bite registration device. After 16 weeks, the angular distortion of Pattern resin was 0.26±0.14 degree(Horizontal angle 0.17±0.14, Vertical angle 0.16±0.11) which was the lowest among the 5 registration device, and that of putty type Exaflex was 0.49±0.35 degree(Horizontal angle 0.42±0.35, Vertical angle 0.17±0.13) which was the highest. The mean amount of distortion variance of Tooth shade acrylic at each experimental period was 0.06±0.08 which was the lowest among the 5 registration device, and that of XCP alone was 0.ll±0.13 which was the highest.

• Journal of Korean society of Dental Hygiene
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• v.17 no.6
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• pp.1053-1065
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• 2017

Objectives: The purpose of this study is to evaluate radiation safety education, knowledge and practice of dental hygienists in using handheld portable intraoral X-ray equipment and to suggest the need for radiation safety education in using handheld portable intraoral X-ray equipment. Methods: We surveyed 223 dental hygienists from July, 2017 to August in the dental clinics of Daejeon, Seoul and Gyeonggi area. Results: Radiation safety educational experience was higher in a year's career (72.9%), than 3 years experience (32.5%) (p<0.05). 82.7% of dental clinic workers took university education for radiation safety education while 55.6% of dental hospital workers took company training (p<0.05). More than 70% of the subjects did not have experience of radiation safety education about using portable intraoral X-ray. Radiation safety knowledge was highest in a year's career (p<0.05). The cumulative dose, radiation sensitivity, and lead defense knowledge were high in all subjects, but knowledge related to scattering radiation and scattering radiation sources was low. Practice of portable intraoral X-ray safety was significantly lower than knowledge. Conclusions: Knowledge of portable intraoral radiography safety is available, but performance is poor. Even with the small amount of radiation exposure, the risk is perceivable. There is a need to actively utilize the provided radiation protection products. In order to do this, efforts should be made to improve knowledge and performance of radiation safety through not only college education but also postemployment training.

• Imaging Science in Dentistry
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• v.45 no.3
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• pp.153-158
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• 2015

Purpose: The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. Materials and Methods: Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. Results: A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. Conclusion: CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption.

• Imaging Science in Dentistry
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• v.35 no.4
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• pp.203-205
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• 2005

Purpose: This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Materials and Methods: Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). Results: The median dose was $491.2{\mu}Gy$ for digital radiography and $1,205.0{\mu}Gy$ for film radiography. The skin entrance dose in digital radiography was significantly lower than that of film radiography (p<0.05). Conclusion: Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.161-167
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• 2018

A clinician's skills in a dental clinic are an important factor in removing the risk factors of patients. Although many universities have conducted educational programs, there has been a limitation on repeated practice because of the limited space and equipment. In dental radiography, there are various intraoral radiographic techniques. Since proficiency in radiography is an important factor in obtaining accurate radiographs, repeated practice and skill learning are important at the pre-clinical stage. However, the recent amendment of diagnostic radiation has caused difficulties in repeated practice on the human body. This study aims to develop a clinical simulator for intraoral radiography that enables repeated practice and self-directed learning without any restriction by utilizing the augmented reality technology to foster clinical skills for dental hygienist.