ABSTRACT
BACKGROUND: With increase of digital imaging, the need for storage space and transmission speed also increases. Compressed images need less storage space and decrease the transmission time. However, compression could compromise image quality. The aim of this study was to evaluate the influence of image compression on the identification of cephalometric points on direct digital lateral cephalogram images, compared with the digital imaging and communications in medicine (DICOM) format. MATERIALS AND METHODS: In this analytical-descriptive study, 19 direct digital lateral cephalograms saved in DICOM format were used. They were converted to joint photographic experts group (JPEG) 2000 format with quality factors 85, 75, and 60 adding up to 76 images (DICOM, JPEG 85, 75, and 60). The images were randomized and eight cephalometric points were identified on each image by a professional, using the x-y coordinate system. Analysis of variance (ANOVA) was applied to investigate if there was a statistically significant difference in the location of cephalometric points between each group of images. All tests were applied at a significance level of 5%. RESULTS: The results did not demonstrate any statistically significant difference in the identification of the eight cephalometric points between the DICOM images and the JPEG2000 quality factors 85, 75, and 60. CONCLUSION: JPEG2000 images of lateral cephalograms with quality factors 85, 75, and 60 did not demonstrate any alterations in the identification of cephalometric points compared with the DICOM format. JPEG2000 is a reliable file format for the compression of digital lateral cephalograms.
ABSTRACT
BACKGROUND: The styloid process and the attached ligaments have the potential for calcification and ossification in specific conditions. The purpose of this study was to evaluate the relationship between the elongated styloid process (ESP) frequency and some of the systemic health factors of patients over 40 years of age. MATERIALS AND METHODS: In this analytical-descriptive study, 296 panoramic radiographs of patients over 40 years of age (165 female and 131 male) referred to the Dental School of Khorasgan Azad University were selected. The length of the styloid process was measured by a special ruler and recorded in a questionnaire form. Other data such as sex, age, height, weight, blood pressure, heartbeat and the number of teeth present in the mouth were also recorded. The lengths equal to or more than 30 mm on the radiographs were considered as ESP. Data analysis were done by independent t-test, Pearson correlation coefficient and Chi-square test at a significance level of < 0.05. RESULTS: ESP was observed in 135 cases (45.6%). There was a significant relationship between ESP and the body height, weight and the blood pressure, but there was no significant correlation between ESP, the heartbeat and the number of teeth present in the mouth. CONCLUSION: Because of the significant relationship between the length of the styloid process and the blood pressure, height and weight it is reasonable to evaluate a patient's systemic health conditions when radiographic signs of ESP are observed.
