The purpose of this study was to evaluate the radiation dose delivered
to radiosensitive organs (thyroid, parotid glands and eye lens) during
dentomaxillofacial imaging with multislice computed tomography (CT),
cone beam CT (CBCT) and panoramic radiographs (orthopantomography, OPT).
The dose was estimated individually for each modality and each clinical
protocol by measuring the absorbed dose at the surface of a head phantom
with thermoluminescence dosimeters. The measured radiation dose was
between 0.01-1.22 mGy for the thyroid gland (systematically outside the
primary beam), 1.34-29.11 mGy for the parotid glands (systematically
exposed to the primary beam) and 0.02-26.22 mGy for the eye lens (in the
primary beam depending on imaging protocol). For all organs, CT was
found to be the most irradiating modality followed by CBCT and OPT.
However, CBCT with a "limited dental" protocol and OPT deliver similar
doses to the parotid glands.