Abstract

Ali Reza, Jafar Hassan and Arman Adibi

The main objective of this study was to evaluate the eyes, parotid and thyroid gland region skin absorbed dose during panoramic radiography with panoramic machine of Oral and Maxillofacial Radiology section of Babol School of Dentistry in Iran. In this research, 273 lif:Mg, Ti thermoluminescent dosemeters (TLDs) (100 LiF:Mg, Ti, harshaw, USA) were used. 90 samples were selected from the patients who referred to the Oral and Maxillofacial Radiology section. For each patient three TLD for eye, parotid and thyroid gland region were carefully applied in each experiment 3 TLD with fixed numbers were used to determine the background radiation. After providing panoramic radiographs, Thermoluminescent signal was read out with a Harshaw 4500 (Harshaw, Bicron USA) reader. Then the data of each TLD number was sent back to us .Mean ± standard deviation was determined by SPSS10 software. Mean ± SD of skin absorbed dose for 90 patients was 0.11 ± 0.075, 0.23 ± 0.15, 0.13 ± 0.079 mg for eyes, parotid and thyroid gland regions respectively. Since Diagnostic Reference level (DRL) of panoramic imaging is unknown in Iran, there is no possibility to compare the current results with DRL. However, it can be stated that the skin absorption dose of thyroid gland in the current study is more than the only reference value of thyroid gland skin absorption dose (0.074 mgy). It can be concluded that an extended study should be done to assess if the decrease of radiation dose without significant reduction of image quality is possible. However there is not a proper reference level to compare the findings, we hope this study play a small role in setting DRL for panoramic imaging in Iran with the help of further studies.