Suk-Ja Yoon

Diagnostic accuracy of panoramic radiography in the detection of calcified carotid artery

OBJECTIVES The purpose of this study was to assess the diagnostic accuracy of the panoramic radiograph in the detection of carotid artery calcification using CT as the gold standard. METHODS 110 dental patients (average age 65.2 years, range 50-82 years) with both panoramic radiographs and CT scans available were selected for the evaluation of carotid artery calcification. Two oral and maxillofacial radiologists interpreted the panoramic radiographs for the presence of carotid artery calcification. CT scans were independently interpreted by a neuroradiologist. RESULTS The accuracy of panoramic radiographs in the detection of carotid artery calcification was 62.3%. The sensitivity and the specificity were 22.2% and 90.0%, respectively. CONCLUSIONS Panoramic radiography has a moderate diagnostic accuracy in the detection of carotid artery calcification, but the sensitivity is low.

Pulp response of mineral trioxide aggregate, calcium sulfate or calcium hydroxide

This study was performed to verify the possibility of MTA and calcium sulfate as a pulp capping agent through comparing the dental pulp response in dogs after capping with MTA, calcium sulfate, and calcium hydroxide. 24 teeth of 2 dogs, 8 month old, were used in this study. Under general anesthesia, cervical cavities were prepared and pulp was exposed with sterilized #2 round bur in a high speed handpiece. MTA calcium hydroxide, and calcium sulfate were applied on the exposed pulp. Then the coronal openin,fs were sealed with IRM and light-cured composite. Two months after treatment, the animals were sacrificed. The extracted teeth were fixed in 10% neutral-buffered formalin solution and were decalcified in formic acid-sodium citrate. They were prepared for histological examination in the usual manner. The sections were stained with haematoxylin and eosin. In MTA group, a hard tissue bridges formation and newly formed odontoblasts layer was observed. There was no sign of pulp inflammatory reaction in pulp tissue. In calcium hydroxide group, there was no odontoblast layer below the dentin bridge. In pulpal tissue, chronic inflammatory reaction with variable intensity and extension occurred in all samples. In calcium sulfate group, newly formed odontoblast layer was observed below the bridge. Mild chronic inflammation with a few neutrophil infiltrations was observed on pulp tissue. These results suggest that MTA is more biocompatible on pulp tissue than calcium hydroxide or calcium sulfate.

Digital panoramic radiographs are useful for diagnosis of osteoporosis in Korean postmenopausal women

OBJECTIVE The purpose of this study was to determine whether digital panoramic radiographs could be used for the diagnosis of osteoporosis through evaluation of the radiographs based on the correlation with bone mineral density (BMD). METHODS One hundred and ninety-four post-menopausal women were selected from participants who had participated in the Dong-gu study. Panoramic radiographic indices measured are mental index (MI), mandibular cortical index (MCI) and simple visual estimation (SVE). BMD at the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometry (DXA). The Pearsons correlation test was performed to analyse the correlation between MI and age and BMD at the lumbar spine, femoral neck and total hip. Multiple linear regression analysis was performed to analyse the association of MI, MCI and SVE with BMD after adjusting for age, height and weight. To determine the optimal cut-off point of MI for the diagnosis of osteoporosis, the receiver operating characteristic analysis was performed. RESULTS The MI was positively correlated with BMDs: lumbar spine: r = 0.36, femoral neck: r = 0.59 and total hip: r = 0.58 (p < 0.001). As age increased, MI decreased (r = -0.46). BMD at the lumbar spine and total hip were significantly lower in participants with reduction of mandibular width, thinning and resorption of mandibular cortex by the MI, SVE and MCI, respectively. The optimal cut-off value of MI for the diagnosis of spinal osteoporosis was 2.22 mm. CONCLUSION Thickness and morphological changes of mandibular inferior cortical bone are associated with BMD, independent of age, height and weight. These results suggest that MI, MCI and SVE may be useful indices for the diagnosis of osteoporosis in a Korean population.

The prevalence and correlation of carotid artery calcification on panoramic radiographs and peripheral arterial disease in a population from the Republic of Korea: the Dong-gu study

OBJECTIVES The aim of this study was to determine the prevalence of carotid artery calcification (CAC) detected on panoramic radiographs and peripheral arterial disease (PAD), and to evaluate the difference in the prevalence of PAD between patients with CAC and patients without CAC detectable by panoramic radiograph. METHODS The surveyed population consisted of 4078 subjects aged 50 years and older (1410 males and 2668 females) who underwent medical and dental examination in Gwangju city, South Korea. Two oral and maxillofacial radiologists interpreted the panoramic radiographs for the presence of carotid artery calcification. A trained research technician measured the ankle-brachial index (ABI). An ABI <0.9 in either leg was considered evidence of PAD. RESULTS The prevalence of CAC on panoramic radiographs was 6.2% and that of PAD was 2.6%. Subjects with CAC had a significantly higher prevalence of PAD than those without CAC (5.5% vs 2.4%, respectively). The presence of CAC on panoramic radiographs was associated with PAD (odds ratio 1.84; 95% confidence interval 1.01-3.36) after adjusting for potential confounders. CONCLUSION CACs detected on panoramic radiographs were positively associated with PAD in middle-aged and older Korean adults.

The correlation of carotid artery calcification on panoramic radiographs and determination of carotid artery atherosclerosis with ultrasonography

OBJECTIVES To investigate the association of carotid artery calcification (CAC) on panoramic radiographs and determine carotid artery atherosclerosis with ultrasonography. STUDY DESIGN The study included 4050 subjects aged 50 years and older. Panoramic radiographs for the presence of CAC were interpreted. Common carotid artery intima-media thickness (CCA-IMT), carotid bulb IMT (CB-IMT), carotid plaques, and the diameter of the common carotid artery (CCA-diameter) were measured by using ultrasonography. RESULTS CB-IMT was significantly greater in male subjects with CAC than in those without CAC. CCA-diameter was significantly greater in subjects with CAC than in those without CAC in both genders. However, there was no significant difference in CCA-IMT. CAC was associated with carotid plaque (for men, odds ratio [OR] 2.14; 95% confidence interval [CI] 1.01-3.36; for women, OR 1.19; 95% CI 0.84-1.67). CONCLUSION CAC on panoramic radiographs was positively associated with IMT and plaque in men and positively associated with carotid diameter in both sexes. CAC on panoramic radiographs was positively associated with carotid atherosclerosis.

Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation.

Purpose This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Materials and Methods Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. Results The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. Conclusion In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

Diagnostic reference levels in intraoral dental radiography in Korea

Purpose The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea. Materials and Methods One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine. Results The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 mGycm2 (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 mGycm2 (DAP). Doses at university dental hospitals were lower than those at dental clinics (p<0.05). Doses of digital radiography (DR) type were lower than those of film-based type (p<0.05). Conclusion We recommend 3.1 mGy (PED), 87.4 mGycm2 (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.

Application of spherical coordinate system to facial asymmetry analysis in mandibular prognathism patients

Purpose The purpose of this study was to compare asymmetric mandibular prognathism individuals with symmetric mandibular prognathism individuals using a new alternate spherical coordinate system. Materials and Methods This study consisted of 47 computed tomographic images of patients with mandibular prognathism. The patients were classified into symmetric and asymmetric groups. Mandibular and ramal lines were analyzed using an alternate spherical coordinate system. The length as well as midsagittal and coronal inclination angle of the lines was obtained. The bilateral differences of the spherical coordinates of the facial lines were statistically analyzed in the groups. Results There were significant differences between the groups in bilateral difference of the length and midsagittal inclination angle of the lines (p<0.05). The bilateral difference of the length and midsagittal inclination angle of the lines has significant correlation with chin deviation (p<0.05). Conclusion The new alternate spherical coordinate system was able to effectively evaluate facial lines. The bilateral difference of lengths and midsagittal inclination of the facial lines might contribute to the facial asymmetry in mandibular prognathism individuals.

Reference dose levels for dental panoramic radiography in Gwangju, South Korea

This study assessed the reference dose levels for dental panoramic radiography in Gwangju city, South Korea based on the dose width product (DWP) and compared them with those already established elsewhere. A total of 44 panoramic dental radiographic sets (36 digital and 8 analogue panoramic sets) in 41 dental clinics in Gwangju city were chosen. The third quartile DWP was determined from 429 surface dose measurements of the adult surface dose in panoramic dental radiography. The third quartile DWP for panoramic radiography was 60.1 mGy mm. The proposed DWP reference levels of 60.1 mGy mm were less than or equal to those previously reported in other countries, such as Italy and UK, and acceptable for panoramic radiography in Gwangju, South Korea.

Diagnostic reference levels for panoramic and lateral cephalometric radiography of Korean children.

AbstractPediatric patients are considered to be more radiosensitive than adults; thus, radiation dose evaluations based on radiologic examinations are particularly important in this population. However, no national diagnostic reference levels (DRLs) are available for pediatric patients in the Republic of Korea. Therefore, the aim of this study was to determine the usage of panoramic and cephalometric radiography under the National Health Insurance (NHI) scheme and to investigate the current DRLs for child panoramic and lateral cephalometric radiography using dose area product (DAP). DAP values were obtained for standard child exposure settings used routinely by dentists. Analysis was performed on data obtained from 28 panoramic and 20 cephalometric x-ray units for the DAP investigation. DRLs for child panoramic and cephalometric radiography were found to be 95.9 mGy cm2 and 121.3 mGy cm2, respectively. These DRLs are higher than those recommended in the UK and Germany, which indicates that further effort is required to reduce pediatric doses in the Republic of Korea.