Absorbed dose reduced by sliced exposure using sector selector system with rotational panoramic radiography

Sliced exposures which restrict the exposed area and adjust the region of diagnosis are possible using a sector selector system which is installed in the rotational panoramic radiograph, PM 2002 CC (Planmeca Oy, Helsinki, Finland). The effects of altering the horizontal and vertical sector selector system on thyroid gland dose were measured using Rando Phantom and thermoluminescence dosimeters. The horizontal sector selector system clarified that the most of the thyroid gland dose was delivered from exposure of the mandibular region. The vertical sector selector system clarified that scattered x-rays which originated from primary x-rays curved at the incisor and canine, premolar and molar, and ramus regions contributed equally to the thyroid gland dose.