• Imaging Science in Dentistry
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• v.31 no.3
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• pp.153-158
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• 2001

Purpose : To determine the head position that the superior border of the mandibular canal as well as mental foramen can be more clearly visualized in panoramic radiography Materials and Methods : Ten dry mandibles were radiographed bilaterally using PM 2002 CC panoramic machine. A 20 mm thick aluminium filter was added to the slit collimator to obtain radiographs with acceptable density. The specimens were tilted by 2, 4, 6, 8, and 10 degrees downward with and without radiopaque markers. Radiopaque markers were inserted into the mandibular canals and the mental canals of each side of the specimens to serve as reference image when assessing the radiographs. The visibility of the mandibular canal and the mental foramen was estimated by 4 observers on all radiographs. The obtained results were analyzed statistically. Results: Mandibular canals were significantly more clearly visible in the radiographs with 4 and 6 degree downward position on both sides (P<0.05). Mental foramens were significantly more clearly visible in the radiographs with 4, 6, and 8 degree downward on right side and 6 degree downward on left side (P<0.05). There was not significant difference between right and left sides. Conclusion: Panoramic radiographs with 4 to 6 degree downward tilting could be valuable in locating the mandibular canal as well as the mental foramen.

• Imaging Science in Dentistry
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• v.33 no.4
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• pp.217-221
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• 2003

Purpose : To evaluate the use of the vertical tube shift from a panoramic film and a periapical film to localize unerupted maxillary incisors and supernumeraries. Materials and Methods : The total of 103 displaced maxillary incisors or embedded supernumeraries were examined in this study. The vertical tube shift technique with panoramic and periapical radiography by normal projection taken and compared to localize the position of the embedded maxillary incisors or supernumeraries by a radiologist and 5 general dentists. The gold standard used for the radiographic comparisons was the true position of the embedded tooth as confirmed by horizontal tube shift technique using three periapical radiographs. The general dentist examiners were instructed on the use of the modified acronym 'SLDOBU' by the radiologist as it pertains to panoramic radiographs as the principle of vertical tube shift. Results: All of the embedded maxillary incisors and supernumeraries were successfully located using the vertical tube shift from a panoramic and a maxillary anterior periapical radiograph by the radiologist and 5 general dentists. Conclusion: The use of a panoramic film with a periapical film combination for a vertical tube shift can be useful to localize unerupted maxillary incisors and supernumeraries.

• Imaging Science in Dentistry
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• v.34 no.2
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• pp.69-74
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• 2004

Purpose : This study was conducted to compare the radiomorphometric indices of the mandible on panoramic radiographs among three groups of normal, osteopenia and osteoporosis and to determine whether panoramic indices have validity in predicting osteoporotic risk. Materials and Methods: Ninty-four postmenupausal women aged 42-72 years (mean 62±7.5) were examined using dual energy X-ray absorptionmetry (DEXA) of the lumbar and classified into three groups by WHO classification. Panoramic mandibular index (PMI), mandibular cortical thickness (Mental index (MI), Antegonial index (AI), Gonial index (G!)) and the mandibular cortical index (MCI) were measured bilaterally on panoramic radiographs and analyzed. Results: There were signigicant differences among normal, osteopenic and osteoporoti groups in PMI (I), PMI (S), MI, AI, GI and MCI. The sensitivities of the MCI (93%) and the combination index of MCI and MI (90%) in diagnosing osteopenic/osteoporotic cases were high. Conclusion: The widths and shapes of the mandibular cortical bone on panoramic radiography may highly reflect the systemic osteopenic/osteoporotic conditions of the patients.

• Imaging Science in Dentistry
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• v.34 no.2
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• pp.91-97
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• 2004

Purpose : This study was performed to evaluate the diagnostic value of both planar and SPECT imagings by comparing the results with the clinical and other imaging modalities findings. Materials and Methods: A total of 578 joints with TMJ complaints were examined using planar scintigraphy and SPECT. The planar scintigraphy and SPECT findings were analyzed and compared to the clinical findings of pain, clicking, crepitus and limitation of mouth opening. Moreover we compared the accuracy of the planar scintigraphy and SPECT methods with the one of the panoramic, transcranial, tomographic and MR imaging methods. Results: The planar scintigraphy and SPECT methods showed a high sensitivity of 0.76-0.84 and low specificity of 0.25-0.45 toward the clinical findings: pain, clicking, crepitus and mouth opening restriction. Simple radionuclide uptake ratio was high in each group of patients with pain, crepitus, limitation of mouth opening (p < 0.05) complaints, in each group with positive bone changes on panoramic, transcranial or tomographic images, and in disc displaced group. Conclusion: Although both planar and SPECT imagings have limited specificity, these techniques are sensitive for detection of internal derangement of the TMJ.

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.67-73
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• 2002

Purpose: To examine the possible relationship between condylar position and disk displacement in the temporomandibular joint. Materials and Methods: 79 temporomandibular joints in 40 patients having temporomandibular disorders were classified into three categories: no disk displacement (NDD) , disk displacement with reduction (DDWR), and disk displacement without reduction (DDWOR). Disk positions were assessed from clinical and MRI findings. The relationship between the three categories and condylar positions was evaluated using lateral individualized corrected tomography. Results: Clinical findings regarding the relationship between condyle and disk positions having anterior, centric, and posterior positions were 27%, 27%, and 46%, respectively, in NDD, 43%, 17%, and 40%, respectively, in DDWR, and 44%, 22%, and 34%, respectively, in DDWOR. There were no significant differences in condylar positions between each of the groups (P>0.05). In the relationship between condyle and disk positions with MRI findings, anterior, centric, and posterior positions were 38%, 38%, and 24%, respectively, in NDD, 29%, 21%, and 50%, respectively, in DDWR, and 44%, 9%, and 47% respectively, in DDWOR. There were significant differences in the condylar positions when MRI was utilized (P<0.05) Conclusion: There was a significant correlation between the condyle and disk positions with MRI findings on lateral individualized corrected tomography.

• Imaging Science in Dentistry
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• v.41 no.1
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• pp.23-28
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• 2011

Purpose : This study was to find the computed tomographic features of fibrous dysplasia of the maxillofacial region. Materials and Methods : All eight cases included in the study reported either to Government Dental College and Hospital or Nair Hospital Dental College, Mumbai between 2003 and 2009. The patients were prescribed computed tomogram in addition to conventional radiographs of maxillofacial region which were studied for characteristic features of fibrous dysplasia. The diagnosis of fibrous dysplasia was confirmed by histopathological report. Results : All cases showed the ill-defined margins of lesions except in the region where the lesions were extending to cortex of the involved bone. Internal structure of all cases showed ground glass appearance. Four cases of maxillary lesion showed the displacement of maxillary sinus maintaining the shape of maxillary sinus. Two cases showed complete obliteration of maxillary sinus. Displacement of inferior alveolar canal did not follow any typical pattern in any of the cases but was displaced in different directions. Conclusion : The craniofacial type of fibrous dysplasia is as common as fibrous dysplasia of jaw. The margins, extent, internal structure and effect on surrounding structure are well detected on computed tomographic images.

• Imaging Science in Dentistry
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• v.38 no.2
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• pp.103-107
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• 2008

Purpose: The purpose of this study was to evaluate the relationship between the position of mesiodens and its complications. Materials and Methods: The subjects for this study consisted of 172 patients with mesiodens. Panoramic radiographs and cross-sectional tomography were taken of all of the subjects. Their clinical records and radiographs were analyzed in order to study the direction and vertical and sagittal position of mesiodens, as well as complications caused by mesiodens. Results: The number of mesiodens was one in 112 cases (65.1%) and two in 60 cases (34.9%). Complications were found in 121 mesiodentes (52.2%), with being median diastema the most frequent. The incidence of complications was high in erupted mesiodens (75.0%), in horizontal mesiodens (89.8%) and in mesiodens located within the arch (75.7%), but was low in mesiodens impacted above apex (29.8%), in normal position (34.4%) and in palatally positioned mesiodens (46.5%). Conclusion: It was suggested that the frequency of complications was different according to the vertical position, the direction of the crown and the sagittal position.

• Imaging Science in Dentistry
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• v.38 no.2
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• pp.89-93
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• 2008

Purpose: To evaluate the difference of the movement of the mandibular condyles between trans cranial and panoramic TMJ radiographs to view the movement of the mandibular condyles. Materials and Methods: Thirty-four paired transcranial and panoramic TMJ radiographs of patients were used to evaluate the movement of the mandibular condyle. The distances, from the most superior point of the mandibular condyle to the most inferior point of the articular eminence on both radiographs, were measured. The measurements were taken at closed state and maximum opening state of each radiograph on both side. Differences between matched pairs were analysed by paired t-test, with significance established at P<0.05. Results and Conclusion: The mean distance, from the most superior point of the mandibular condyle to the most inferior point of the articular eminence on both radiographs, was statistically different at each side (P<0.05). At closing state, the mean distance measured on panoramic TMJ radiographs was longer than on transcranial radio-graphs (0.85 mm at right side, 1.20 mm at left side). But at maximum opening state, the mean distance on transcranial radiographs was longer (1.00 mm at right side, 0.62 mm at left side) than panoramic TMJ radiographs.

• Journal of the Korean Society of Radiology
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• v.8 no.1
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• pp.11-18
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• 2014

The purpose study is to investigate the correlation between cardiovascular symptoms and factors in police officers, to provide basic data for a systematic and effective resource management of radiation workers in the future. This study was conducted on police officers who visited the national police hospital and who underwent 201Tl-SPECT for the diagnosis of cardiovascular diseases. In study result, smokers than non-smokers 1.80 times higher cardiovascular disease. Beside, person with hypertension than those who do not have hypertension 1.63 times higher cardiovascular disease. And, the probability of cerebrovascular disease was 1.82 times higher in patients with a low HDL level.

• Imaging Science in Dentistry
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• v.34 no.3
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• pp.159-164
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• 2004

Purpose: To compare alveolar bony height of pantomograph with bony height of thin slice, multiplanar reformatted (MPR) Computed Tomograph. Materials and Methods : Panoramic radiograms of 12 young adult patients had been taken by one radologic technitian and the measurements were corrected by magnification ratio (1.20). The slice thickness of Multi-detector Computed Tomography (CT) was at least 1mm for the accuracy. The raw CT datas were imported into the V-works 4.0 (CyberMed Corp., Seoul, Korea) and transformed to MPR images. Pantomographic measurements of alveolar bone were compared to CT values by average mean bony height measurements for the accuracy. Inter-, and Intra-observer variability was evaluated. Results : There was no significant differences between height measurement of pantomography and that of CT (P>0.05). There were no significant differences in either inter-or intra-observer measurements (P>0.05). Conclusion : Pantomography showed relatively high accuracy and precision in measuring alveolar bony height.