• Imaging Science in Dentistry
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• v.39 no.3
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• pp.157-161
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• 2009

Purpose : This study aimed to investigate the luminal stenosis of the internal carotid artery with calcification detected on panoramic radiographs. Materials and Methods : This study used fifty carotid arteries of 36 dental patients whose panoramic radiograph and computed tomography angiography (CTA) revealed the presence of carotid artery calcification. A neuroradiologist interpreted CTA to determine the degree of stenosis of the internal carotid arteries. The degree of stenosis was stratified in four stages; normal (no stenosis), mild stenosis (1-49%), moderate stenosis (50-69%) and severe stenosis (70-99%). Results : Among the fifty carotid arteries with calcification detected on both panoramic radiography and CTA, 20 carotid arteries (40%) were normal, 29 carotid arteries (18%) had mild stenosis, 1 carotid artery (2%) had moderate stenosis, and there was none with severe stenosis. Conclusion : Sixty percent of the carotid arteries with calcification detected on both panoramic radiography and CTA had internal luminal stenosis, and two percent had moderate stenosis. When carotid atheroma is detected on panoramic radiograph, it is possible that the dental patient has luminal stenosis of the internal carotid artery.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.275-282
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• 1999

Purpose: The objective of this study was to compare clinical examination of dental caries and secondary caries with panoramic examination. and to examine bone lesions and dental anomaly of unerupted state. Materials and Methods: In this study. clinical records and panoramic radiographs were available for 89 first grade students in elementary school. Dental caries of occlusal surfaces. proximal surfaces. and buccolingual surfaces were examined. Secondary caries was examined too. In addition. the central lesion and dental anomaly of unerupted state were examined in panoramic radiographs. Results: The obtained results were as followed: 1. Carious detectability of clinical examination in occlusal and buccolingual surface was higher than that of panoramic examination. but it is statistically insignificant(p>0.05). In proximal surface. carious detect ability of panoramic examination was higher than that of clinical examination. and it is statistically significant(p<0.01). 2. In contrast to clinical examination only. when the two examination methods were combined. there was additional detection of dental caries(26.7％ in occlusal surface. 48.2％ in proximal surface. 33.3％ in buccolingual surface. and 38.3％ totally). 3. In detection of secondary caries. panoramic examination had lower ability than clinical examination in all three surfaces. but in case that both methods were combined. totally 36.0％ extra carious lesions were detected. 4. In panoramic examination. detectability of secondary caries in upper teeth is lower than lower teeth. 5. In panoramic examination. it was possible to detect the central lesions and dental anomalies of unerupted state which cannot be detected in clinical examination. Conclusion: It is useful to combine the panoramic examination with clinical examination in order to increase carious detectability and to evaluate the central lesions and dental anomalies of unerupted state

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.9-14
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• 2007

Purpose : To determine the more valuable information to detect the mandibular canal and the mental foramen in panoramic radiographs of a selected Korean population for the implant. Materials and Methods : This study analysed 288 panoramic radiographic images of patients taken at the Dental hospital of Chosun University retrospectively. Indirect digital panoramic X-ray machine (ProlineXC, PLANMECA, Finland) with processing by using Directview $CR950^@$ (Kodak, U.S.A.) and Direct digital panoramic X-ray machine (Promax, PLANMECA, Finland) were used for all exposures. All images were converted into Dicom format. Results : The common position of the mental foramen was in line with the longitudinal axis of the second premolar (68.1%). The mental foramen was symmetrical in 81.8% of cases. The mandibular canal was not identified at anterior portion and discontinued with the mental foramen in 27.8% of all cases, in 42.4% identified with lower border line continued with the mental foramen, in 14.6% with both upper and lower border lines, and in 15.3% unilaterally identified with lower border line. Conclusion : Clinicians can estimate the upper border line of the mandibular canal from the confirmation of the mental foramen and the lower border line of the mandibular canal symmetrically on the panoramic radiography taken in adjusted midsaggital plane of patient's head.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.261-269
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• 1998

With the CT findings as gold standard, the sensitivity, the specificity, and the diagnostic accuracy of Waters' radiography and Waters' radiography with panoramic radiography were compared in the diagnosis of antral mucosal thickening of 16 patients. Three oral radiologists and three non-oral radiologists interpreted the Waters' radiographs and after 4 weeks, interpreted the Waters' radiographs and panoramic radiographs simultaneously. The interpretation point was the existence or the non-existence of the mucosal thickening on the medial, the posterolateral, the floor, and the roof of maxillary sinus. The obtained results were as followed : 1. In oral radiologist group, the sensitivity, specificity and diagnostic accuracy of Waters' film were 0.7250, 0.8489 and 0.7578 respectively. 2. The sensitivity and the diagnostic accuracy in oral radiologist group were higher than those of non-oral radiologist group (P<0.05), but there was no significant difference between two groups in the specificity (P>0.05), 3. There was no significant difference of the diagnostic abilities except the specificity in oral radiologist group between Waters' radiography and Waters' radiography with panoramic radiography (P>0.05). 4. The sensitivity and the diagnostic accuracy were the highest in the case of medial wall interpretation, the specificity was the highest in the posterolateral wall. 5. In the posterolateral wall and the floor, the sensitivity and the diagnostic accuracy of oral radiologist group were higher than those of non-oral radiologist group (P<0.05).

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.61-66
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• 2002

Purpose: To compare the bone height of implant sites measured using panoramic radiography and spiral CT. Materials and Methods : The available bone height was determined for 263 maxillary and mandibular implant sites in 59 patients. Distortion was calculated using the metal bar for the panoramic radiographs. Results: Significant differences in mean bone height between the two imaging modalities were found in maxillary and mandibular anterior regions (p<0.05). The mean difference in bone height recorded by the two techniques was smallest in the maxillary and mandibular molar areas (0.8 mm), and greatest in the mandibular anterior region (1.3 mm). With the exception of the mandibular anterior region, ninety percent of all the sites showed measurement differences within 2 mm. Conclusion: A safety margin of 2 to 3 mm is called for when utilizing panoramic radiography, otherwise additional imaging modality such as computed tomography is necessary to obtain accurate measurements.

• Imaging Science in Dentistry
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• v.48 no.4
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• pp.255-259
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• 2018

Purpose: This study proposes a new ball-type phantom for evaluation of the image layer of panoramic radiography. Materials and Methods: The arch shape of an acrylic resin phantom was derived from average data on the lower dental arch in Korean adult males. Metal balls with a 2-mm diameter were placed along the center line of the phantom at a 4-mm mesiodistal interval. Additional metal balls were placed along the 22 arch-shaped lines that ran parallel to the center line at 2-mm buccolingual intervals. The height of each ball in the horizontal plane was spaced by 2.5 mm, and consequently, the balls appeared oblique when viewed from the side. The resulting phantom was named the Panorama phantom. The distortion rate of the balls in the acquired image was measured by automatically calculating the difference between the vertical and horizontal length using $MATLAB^{(R)}$. Image layer boundaries were obtained by applying various distortion rate thresholds. Results: Most areas containing metal balls (91.5%) were included in the image layer with a 50% distortion rate threshold. When a 5% distortion rate threshold was applied, the image layer was formed with a small buccolingual width along the arch-shaped center line. However, it was medially located in the temporomandibular joint region. Conclusion: The Panorama phantom could be used to evaluate the image layer of panoramic radiography, including all mesiodistal areas with large buccolingual width.

• Imaging Science in Dentistry
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• v.44 no.1
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• pp.1-6
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• 2014

Professionals performing radiographic examinations are responsible for maintaining optimal image quality for accurate diagnoses. These professionals must competently execute techniques such as film manipulation and processing to minimize patient exposure to radiation. Improper performance by the professional and/or patient may result in a radiographic image of unsatisfactory quality that can also lead to a misdiagnosis and the development of an inadequate treatment plan. Currently, the most commonly performed extraoral examination is panoramic radiography. The invention of panoramic radiography has resulted in improvements in image quality with decreased exposure to radiation and at a low cost. However, this technique requires careful, accurate positioning of the patient's teeth and surrounding maxillofacial bone structure within the focal trough. Therefore, we reviewed the literature for the most common types of positioning errors in panoramic radiography to suggest the correct techniques. We would also discuss how to determine if the most common positioning errors occurred in panoramic radiography, such as in the positioning of the patient's head, tongue, chin, or body.

• Imaging Science in Dentistry
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• v.49 no.4
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• pp.287-294
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• 2019

Purpose: This study was performed to analyze the clinical and imaging features of contemporary osteomyelitis(OM) and to investigate differences in these features on panoramic radiography according to patients' history of use of medication affecting bone metabolism. Materials and Methods: The records of 364 patients(241 female and 123 male, average age 66.8±14.9 years) with OM were retrospectively reviewed. Panoramic imaging features were analyzed and compared between patients with medication-related OM(m-OM) and those with conventional, medication-unrelated OM(c-OM). Results: The age of onset of OM tended to be high, with the largest number of patients experiencing onset in their 70s. The 2 most frequent presumed causes were antiresorptive medication use (44.2%) and odontogenic origin (34.6%). On panoramic radiographs, a mix of osteolysis and sclerosis was the most common lesion pattern observed (68.6%). Sequestrum, extraction socket, and periosteal new bone formation were found in 143(42.1%), 79 (23.2%), and 24 (7.1%) cases, respectively. The m-OM group exhibited sequestrum and extraction socket more frequently and displayed significantly higher mandibular cortical index values than the c-OM group. Conclusion: We observed some differences in imaging features as shown on panoramic radiography according to the history of antiresorptive medication use. This study may help elucidate the predictive imaging features of medication-related osteonecrosis of the jaw.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.255-260
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• 1999

Purpose: The objective of this study was to evaluate the possibility of substitution of the zonography for the full-mouth periapical radiography in aspect of radiation protection. Materials and Methods: Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses at brain, skin above the TMJ. parotid gland. bone marrow in the mandibular body. and thyroid gland during the full-mouth periapical radiography. panoramic radiography. and zonography were measured. Resul ts: From the zonography. the absorbed doses to the brain. the skin over the TMJ. and the parotid gland were relatively high. but the absorbed doses to the bone marrow in the mandibular body and. especially. the thyroid gland were very low. Conclusion: The zonography can be an alternative to the full-mouth periapical radiography in aspect of radiation protection.

• Imaging Science in Dentistry
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• v.44 no.2
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• pp.95-102
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• 2014

Purpose: This study was performed to evaluate the reproducibility of panoramic radiographs of dentulous and edentulous patients. Materials and Methods: The reproducibility of panoramic radiographs was evaluated using the panoramic radiographs acquired from 30 anterior dentulous patients by using a common biting positioning device (dentulous group) and 30 anterior edentulous patients by using chin-support devices to take a panoramic radiograph (edentulous group), respectively; these patients had undergone 3 or more panoramic radiographs. The widths and angles between the designated landmarks were measured on the panoramic radiographs, and the reproducibility was evaluated using the intraclass correlation coefficient (ICC) and the coefficient of variation. Results: In the dentulous and edentulous groups, the ICCs of the mandibular ramus and mandibular angle areas were higher than the condylar head and zygomatic areas. The mandibular ramus and angle areas showed statistically lower mean coefficients of variation than the condylar head and zygomatic areas in the dentulous group. The mandibular angle area showed a significantly lower mean coefficient of variation than the zygomatic area in the edentulous group. By comparing the two groups, each ICC of the edentulous group was lower than that of the dentulous group, and the mean coefficients of variation of the mandibular ramus area, zygomatic area, left condylar inclination, and ramus ratio between the right and the left in the edentulous group were significantly higher than those in the dentulous group. Conclusion: Biting positioning for dentulous patients provided better positioning reproducibility than chin-support positioning when performing panoramic radiography for edentulous patients.