How to assess tonsilloliths and styloid chain ossifications on cone beam computed tomography images.

OBJECTIVE: The aim of this study was to establish an anatomical guideline in cone beam computed tomography (CBCT) images to discriminate soft-tissue calcifications, specifically, tonsilloliths, and styloid chain ossification (SCO) in the multiplanar reconstruction screen of the i-CAT Vision. MATERIALS AND METHODS: We analyzed 100 pairs of CBCT images and panoramic digital radiographies regarding the presence or absence of tonsilloliths and SCO. The intraobserver agreement varied from excellent to good. The statistical analyses included Mann-Whitney test, chi-square test, Spearman test, Student's t-test, and Wilcoxon test. The analyses were repeated without the guideline to verify its effectiveness. RESULTS: A total of 25 tonsilloliths were found in panoramic images while CBCT images revealed 60. Panoramic and CBCT images showed 42% and 63% of patients positive to SCO, respectively. We found a statistically significant difference when comparing the presence of tonsilloliths and SCO between panoramic and CBCT images (Wilcoxon test P < 0.05). The analyses without the guideline showed that the observer tended to diagnoses more false-positive SCO. CONCLUSION: Based on the results, we can suggest that CBCT images are more suitable to differentiate tonsilloliths and SCO than panoramic images. The guideline was more important to diagnosis SCO than tonsilloliths. SCO was misclassified in 34% without the guideline.

Evaluation of proximal caries in images resulting from different modes of radiographic digitalization.

OBJECTIVE: The aim of this study was to evaluate the performances of observers in diagnosing proximal caries in digital images obtained from digital bitewing radiographs using two scanners and four digital cameras in Joint Photographic Experts Group (JPEG) and tagged image file format (TIFF) files, and comparing them with the original conventional radiographs. METHOD: In total, 56 extracted teeth were radiographed with Kodak Insight film (Eastman Kodak, Rochester, NY) in a Kaycor Yoshida X-ray device (Kaycor X-707; Yoshida Dental Manufacturing Co., Tokyo, Japan) operating at 70 kV and 7 mA with an exposure time of 0.40 s. The radiographs were obtained and scanned by CanonScan D646U (Canon USA Inc., Newport News, VA) and Genius ColorPage HR7X (KYE Systems Corp. America, Doral, FL) scanners, and by Canon Powershot G2 (Canon USA Inc.), Canon RebelXT (Canon USA Inc.), Nikon Coolpix 8700 (Nikon Inc., Melville, NY), and Nikon D70s (Nikon Inc.) digital cameras in JPEG and TIFF formats. Three observers evaluated the images. The teeth were then observed under the microscope in polarized light for the verification of the presence and depth of the carious lesions. RESULTS: The probability of no diagnosis ranged from 1.34% (Insight film) to 52.83% (CanonScan/JPEG). The sensitivity ranged from 0.24 (Canon RebelXT/JPEG) to 0.53 (Insight film), the specificity ranged from 0.93 (Nikon Coolpix/JPEG, Canon Powershot/TIFF, Canon RebelXT/JPEG and TIFF) to 0.97 (CanonScan/TIFF and JPEG) and the accuracy ranged from 0.82 (Canon RebelXT/JPEG) to 0.91 (CanonScan/JPEG). CONCLUSION: The carious lesion diagnosis did not change in either of the file formats (JPEG and TIFF) in which the images were saved for any of the equipment used. Only the CanonScan scanner did not have adequate performance in radiography digitalization for caries diagnosis and it is not recommended for this purpose.

Clinical evaluation of the effects of radiographic distortion on the position and classification of mandibular third molars.

OBJECTIVE: Panoramic radiographs are routinely employed for surgical planning of unerupted third molars. The objective of this study was to evaluate distortions in the position of mandibular third molars on panoramic radiographs. MATERIALS AND METHODS: Panoramic radiographs of 14 patients with indication for extraction of the mandibular third molars were used. Transurgical impressions of the crowns of the teeth to be extracted and adjacent second molars (n=19) were achieved with addition silicone and poured with type IV plaster for comparison of the inclinations of the third molars on the radiographs and study casts. RESULTS: There was a mean difference of -5.37 degrees between the position of the third molar on the panoramic radiograph and on the study cast (standard deviation 1.46, P<0.05, Student's t-test). CONCLUSION: There is distortion in the position of teeth on the panoramic radiograph, which may influence the surgical planning; however, this does not invalidate it as the main tool for diagnosis and surgical planning of mandibular third molars.