Absorbed dose to the eye lens during dental radiography

Radiographic examinations have clinical validation/relevance in dental practice. Dentists pay strong attention to absorbed doses to the eye lens, which is located near or inside the irradiation field. Recently, the ICRP recommended a new threshold dose for the eye lens. Therefore, we carried out eye lens dose measurements using a head phantom. We affixed fluorescence glass dosimeters to a head phantom and measured the absorbed doses during intraoral radiography, panoramic radiography, cephalography, helical scan computed tomography (helical CT), and dental cone beam computed tomography (dental CBCT). The mean absorbed dose to the eye lens in intraoral radiography examinations for maxillary incisor teeth and molar teeth was 0.11 +/- 0.09 and 0.08 +/- 0.04 mGy, respectively. Corresponding values in occlusal method examinations for the maxillary (craniocaudal angulation 70A degrees parallel to the occlusal plane) and mandibular (craniocaudal angulation 90A degrees) regions were 0.19 +/- 0.01 and 0.19 +/- 0.07 mGy, respectively. The mean value for panoramic radiography examinations was 0.07 +/- 0.02 mGy, while that for cephalography examinations in the posteroanterior projection and left lateral projection was 0.02 +/- 0.00 and 0.18 +/- 0.02 mGy, respectively. The corresponding value for helical CT was 11.87 +/- 1.12 mGy, while those for dental CBCT of the front teeth and molar teeth were 0.07 +/- 0.02 and 0.12 +/- 0.09 mGy, respectively. Eye lens doses ranged between 0.02 and 0.19 mGy in individual radiographic examinations, including CBCT. Although helical CT recorded 11.87 mGy, it was still lower than the recent ICRP-recommended threshold (500 mGy).