To evaluate the potential feasibility of cone beam computed tomography (CBCT) in the assessment of trabecular bone microarchitecture.
Sixty-eight specimens from four pairs of human jaw were scanned ...using both micro-computed tomography (micro-CT) of 19.37-μm voxel size and CBCT of 100-μm voxel size. The correlation of 3-dimensional parameters between CBCT and micro-CT was evaluated.
All parameters, except bone-specific surface and trabecular thickness, showed linear correlations between the 2 imaging modalities (P < .05). Among the parameters, bone volume, percent bone volume, trabecular separation, and degree of anisotropy (DA) of CBCT images showed strong correlations with those of micro-CT images. DA showed the strongest correlation (r = 0.693).
Most microarchitectural parameters from CBCT were correlated with those from micro-CT. Some microarchitectural parameters, especially DA, could be used as strong predictors of bone quality in the human jaw.
Objectives The purpose of this study is to investigate the effects of different bit depths and kilovoltage peak (kVp) values used in intraoral digital radiography on observer performance in detecting ...subtle radiographic density differences. Study design Using an intraoral CCD sensor set at 8- or 12-bit depth, kVp set at 60 or 70, and 14 different exposure times, digital radiographs were acquired of a specially designed aluminum step-wedge phantom with small holes of different depths in each step. Ten observers examined all images. Results The observers counted more holes with the 12-bit images compared with the 8-bit images, particularly at 60 kVp. Significantly more holes were also counted with images taken at 70 kVp compared with those taken at 60 kVp. Conclusion Regarding the detection of subtle radiographic density differences, 12-bit images and 70 kVp were superior to 8-bit images and 60 kVp.
Objective To characterize the presentation of C-shaped canals in mandibular molars on dental panoramic radiographs. Study design The sample consisted of 290 patients who had undergone both panoramic ...dental radiography and computed tomography (CT). Initially the presence of mandibular molars with C-shaped canals was identified on this sample by the use CT. This was used as a ground radiographic truth. Then 3 investigators independently classified the mandibular molars according to their 6 root morphologies on panoramic dental radiographs. The sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) of characteristic findings on panoramic radiographs were calculated. Results A C-shaped canal was identified in 90 (29%) of 311 mandibular molars. The most common morphology of C-shaped canal molars was 2 separate conical roots (52%); trabecular patterns were relatively common between the roots. In contrast, the most common morphology of molars without C-shaped canals was 2 separate roots that were either divergent or parallel (85%). Conclusion Panoramic radiography is a good surveying modality to detect C-shaped canals and can be used to determine whether further examination is required before endodontic treatment.
Objectives To examine the effects of the luminance and bit depth of digital image on observer performance for determination of endodontic file positioning. Study design Using extracted premolar ...teeth, no. 08 K-file was placed into the canal and positioned so that the tip was either flush or 1 mm short of the radiologic root apex. The samples were imaged with both conventional and digital radiographs at 8 and 12 bits. Eleven observers read the images under dark and bright condition, and receiver operating characteristics analysis was performed. Additionally, the interpreting time was measured. Results The 12-bit images showed similar observer performance compared with conventional images, and better than the 8-bit images. The interpretation time for bright condition and 8-bit images was longer than for dark condition and 12-bit images. Conclusion Twelve-bit digital images were preferred to 8-bit for accurate determination of endodontic file position.
Objective The objective of this study was to evaluate the relationship between sialographic images and clinical symptoms of inflammatory parotid gland diseases. Materials and methods Clinical ...symptoms including swelling, pain, the duration of these symptoms, and degree of salivation were examined on 83 parotid glands from 64 patients. Swelling and pain were classified into 4 categories. Duration of any symptom was recorded in months and the degree of salivation was classified into 4 groups by inspection and massage. Sialography was performed and panoramic radiographs were taken later to examine the evacuation state of the contrast medium. The degree of inflammation on sialographic images was evaluated in 3 areas (the main duct, the intraglandular duct, and the parenchyma) by rating 4 grades respectively under the consensus of 3 radiologists. A Fisher's exact test and a Pearson correlation were used for statistical analyses. Results The degree of salivation showed significant correlation between the presence of inflammation and the grades of inflammation on sialographic images. There was also a correlation between the grades of inflammation of the sialographic images and the amount of retention of the contrast medium. There was no significant relationship between the grades of inflammation of the sialographic images with swelling or pain. Conclusion The grade of inflammation of a sialographic image has correlated with a degree of salivation.
