The Comparison of Entrance Surface Radiation Dose to the Thyroid Gland Region in Different Dental Panoramic Radiography

Introduction: The proven radio sensitivity and the position of the thyroid gland make it a significant organ during the dental radiography exposure. Objectives: This study compared the surface radiation dose to the thyroid gland region during two different techniques of two dimensional (2D) conventional orthopantomography (OPG) and three dimensional (3D) OPG reconstructed from cone beam computed tomography (CBCT). Methods: The entrance surface dose to the thyroid region of the patients was evaluated using a personal dosimeter in a sample of 156 patients who prescribed for an OPG examination. Results: The obtained mean dose values for conventional OPG and reconstructed OPG from CBCT are 7.47 µSv and 28.65 µSv, respectively. Further a significant difference (p < 0.05) was observed between those two doses. Conclusions: A significant amount of dose reduction to the thyroid gland region can be obtained when using conventional OPG compared to the CBCT.