Estimating the radiation surface dose and measuring the dose area product to provide the diagnostic reference level in panoramic radiography

Background: Panoramic radiography is one of the common dental imaging procedures using ionizing radiation. It is necessary to control the level of exposure and use the optimized levels. So, the current work aimed to estimate the surface absorbed doses of critical organ regions, namely thyroid and parotid glands. Moreover, dose area product (DAP) values were measured and a local DRL was then established for panoramic radiography. Materials and Methods: The data from 201 patients including 141 adults and 60 children (5-10 years) were used for this cross-sectional study. Seven panoramic radiography systems were selected from 6 radiology clinics in Yazd province. For each patient, 12 thermoluminescence dosimeters (TLD GR-200) were used to obtain the surface absorbed dose in both the thyroid and parotid gland regions. The DRL values were calculated using DAP values in terms of the ICRP recommendation. Results: The mean and standard deviation (SD) of thyroid and parotid glands’ surface absorbed doses were equal to 60.6±3.7 and 290±12.4 μGy in the adult group, respectively. In the children group, these values were 40.7±2 and 189.3±11.5 μGy, respectively. Moreover, the local DRL values were obtained as 99.7 and 73.4 mGy.cm2 for the adults and children groups, respectively. Conclusion: The higher surface absorbed dose values in the adult group can be related to the use of higher radiation parameters. The local DRL proposed for the adult and pediatric groups in the current study was relatively lower than those established by other reports, which seemed acceptable for panoramic radiography in Yazd, Iran.