No abstract available.
Diagnosis* ; Molar* ; Radiography, Panoramic*

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.
Head ; Mandible ; Radiography ; Radiography, Panoramic*

PURPOSE: To evaluate the magnification error percentage in repeatedly taken panoramic radiographs of same patient and machine. MATERIALS AND METHODS: 92 panoramic radiographs from 46 patients were traced and 30 horizontal and vertical measurements were made with digital sliding caliper. The results were compared with paired t-test. RESULTS: There was no statistically significant difference between the two measurements. The overall difference as percentage error was 6.19+/-5.60%. The largest error as 14.61+/-12.44% was found at condylar height 1, and smallest as 1.86+/-1.61% at mandibular height. Overall vertical error excluding condylar height 1 was 3.76+/-3.97%, and the horizontal error 6.88+/-5.92%. CONCLUSION: Repeatedly taken panoramic radiographs of the same patient and machine was reliable since there was no significant percentage error difference but the percentage error ranged from 1.86+/-1.61% to 14.61+/-12.44% indicating the error depends on the measuring site.
Diagnostic Imaging ; Humans ; Radiography, Panoramic*

PURPOSE: Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues. MATERIALS AND METHODS: A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device. RESULTS: Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block. CONCLUSION: Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.
Humans ; Radiography, Panoramic ; Reproducibility of Results

ABSTRACT Panoramic X-ray is well known to cause DNA damage and induces cellular death. The aim of the present study was to evaluate the cytotoxicity of radiation exposure from panoramic radiography on human buccal mucosa cells by assessing the cell viability using the simple-trypan blue exclusion test. The genotoxicity effect was evaluated by assessing comet assay score. This research included a total of 20 healthy patients who had panoramic radiography for a routine dental examination. Buccal mucosa cells were collected from all participants before X-ray exposure and at 30 min or 24 h after exposure in Groups 1 and 2, respectively, and subjected to a comet assay and trypan blue exclusion test to assess cell viability and DNA damage. Cell viability was calculated as the ratio of live (translucent) to total counted cells. Comet assay output images were analysed using OpenComet software and a visual score by measuring the percentages of tail DNA and summing the visual score, respectively. A statistically significant (p < 0.05) reduce in cell viability was observed at 30 min after exposure, furthermore there is no more reduction after 24 h. Both comet assay measurements showed a significant (p < 0.05) increase in the percentage of tail DNA and visual score at 30 min after exposure, then tend to decrease after 24 h of exposure, although it was not significant (p > 0.05). The results showed that panoramic radiography interfered cell viability and induced DNA damage in buccal mucosa cells within 30 min after exposure, but these effects were ceased after 24 h.
Mouth Mucosa--cytology ; Radiography, Panoramic

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.
Bicuspid ; Bone Density* ; Humans ; Mandible ; Radiography, Panoramic

PURPOSE: The objective of this study was to compare clinical examination of 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 detectability 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 secodary 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
Dental Caries* ; Diagnosis* ; Humans ; Radiography, Panoramic* ; Tooth

PURPOSE: To make a focal trough (image layer) for an average maxillary dental arch of 6-year-old korean in panoramic radiography. MATERIALS AND METHODS: Phantom for the maxillary dental arch was designed using intercanine width, intermolar width, tooth size, and interdental spacing to record the data of 6-year-old child. The characteristics of pre-corrected panoramic machine (for adult) was evaluated using the phantom, resolution test pattern for margin of the image layer, and metal ball for the center of the image layer. Panoramic image layer of the child was developed by means of decreasing the speed of film-cassette and positioning the phantom backwards, and then the characteristics of post-corrected panoramic machine (for child) were reevaluated. RESULTS: At post-corrected panoramic image layer, beam projection angles at all interdental areas increased for about 2.6-3.8 degrees, the position of the image layer was shifted toward the rotation center for about 2.5 mm at the deciduous central incisior area. The width of image layer decreased at all areas. CONCLUSION: Increased beam projection angle will reduce the disadvantage of tooth overlap, and the same form between the center of the image layer and dental arch will improve image resolution.
Child* ; Dental Arch ; Humans ; Radiography, Panoramic ; Tooth

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.
Head ; Humans ; Radiography, Panoramic ; Reproducibility of Results

PURPOSE: To establish reference doses of periapical radiography in Chonnam Province, Korea. MATERIALS AND METHODS: The target-skin distances were measured for dental patient's 1235 exposures including 345 mandibular molar areas. Each periapical radiation exposure was simulated with exactly the same patients exposure parameters and the simulated radiation doses were measured utilizing Mult-O-Meter (Unfors Instruments, Billadal, Sweden). The measurements were done in 44 dental clinics with 49 dental x-ray sets in Chonnam Province for one or two weeks at each dental clinic during year 2006. RESULTS: The third quartile patient surface doses were 2.8 mGy for overall periapical exposures and 3.2 mGy for periapical mandibular molar exposures. CONCLUSION: The third quartile patient surface doses in Chonnam Province can be used as a guide to accepted clinical practice to reduce patient radiation exposure for the surveyed reference doses were below the recommended dental periapical radiography dose of 7 mGy by IAEA.
Dental Clinics ; Humans ; Molar ; Radiography, Panoramic