Comparison of the absorbed dose of target organs in conventional and digital lateral cephalometric radiography

Due to the widespread use of lateral cephalometric radiography especially in orthodontic therapy and orthognathic surgery, obtaining radiographs of high quality with the least amount of radiation exposure is of utmost importance. The aim of this study was to compare the absorbed dose of head and neck target organs in conventional and digital lateral cephalometric radiography. In this experimental study, RANDO phantom was used for absorbed dose estimation in thyroid, parotid, pituitary and submandibular glands, bone marrow and ocular lens. The phantom was exposed 60 times: 30 times with CRANEX Tome, Soredex and 30 times with CRANEX D, Soredex with standard exposure settings. TLD [GR-200] dosimeters were used to measure organ doses. A total of 69 TLDs were used with 9 TLDs for background radiation. T-test was used for statistical analysis. The mean absorbed dose of target organs was 0.04 +/- 0.005 mSv for conventional and 0.01 +/- 0.002 mSv for digital technique. The difference in absorbed dose in all target organs except for the thyroid gland [P=0.08] between the two techniques of conventional and digital was statistically significant. [P=0.01] $ Use of digital lateral cephalometric system causes a significant reduction in absorbed dose compared to the conventional film-screen system

[Evaluation of periodontal parameters in postmenopausal women]

It has been suggested that osteoporosis may be a predisposing factor for periodontitis and tissue destruction, thus periodontitis and mandibular bone density might be related. The purpose of the present study was to evaluate the clinical signs of periodontal tissue destruction in postmenopausal women. In this cross-sectional study, 60 postmenopausal women [51 to 78 years of age] underwent radiographic examination of the right mandibular premolar. Mandibular bone density [MBD] was measured using optical densitometry. Periodontal status variables examined included: probing pocket depth [PPD], clinical attachment level [CAL], bleeding on probing [BOP] and plaque index [PLI]. Data were analyzed by statistical tests using P<0.05 as the limit of significance. This study found no statistically significant association between the four indicators of periodontal disease and mandibular bone density, but there was statistically significant association between mandibular bone density and the number of remaining teeth. There was also statistically significant association between PPD and the number of remaining teeth. These findings suggest that individuals with high MBD seem to retain teeth with deep periodontal pockets more easily than those with lower MBD

Evaluation of interproximal caries with using of bitewing radiography in dental student of Islamic Azad University

Statement of Problem: Dental caries is one of the common diseases in the world. It is an infective disease which is caused by loss of minerals and destruction of dental tissues. One of the most effective ways to diagnose the interproximal caries is radiography. Bitewing radiography is the best way for caries diagnosis

Purpose: The aim of this study was to evaluate the prevalence of the interproximal caries in dental students of Islamic Azad University

Materials and Methods: This research was a cross sectional study that was conducted on 89 students of the Azad University consisting of 48 females and 41 males who were selected by random sampling. For each individual student left and right posterior bitewing radiographs were taken with a standard method [the interproximal spaces were between 6- 7, 5, 6 and 4, 5]. Thus 12 interproximal spaces were examined in each individual. The most proximal cavitation surfaces were detected in the upper Jaw

Results: Results revealed that 6 individuals [6.7%] were totally caries free and 83 individuals [93.3%] showed interproxmal caries. Out of 1068 proximal spaces which had been studied 794 Spaces [73.4%] were caries free and 274 surfaces [25.7%] had caries

Conclusion: The high incidence of proximal caries and the possibility of missing them in the routine examinations make the bitewing radiographs an effective procedure for diagnosis