Radiation dosimetry in tomography of the teeth and jaws using a multi-film cassette

The absorbed doses and energy imparted in lateral and antero-posterior tomography of the teeth and jaws were measured. A multi-film cassette with 5 films was exposed using a diameter of the circular collimator of 1.5 cm. With one exception, the absorbed doses were below 1 mGy. The parotid gland towards the roentgen tube received about 2 mGy in lateral tomography of the mandibular third molar. The energy imparted in lateral tomography was 0.6 mJ and in antero-posterior tomography about 2.5 mJ. Since the radiation doses in tomography of the teeth and jaws were low compared with estimated risk levels, they should not deter from using tomography.