Objective: The needs of intraoral radiography are increasing for home care and especially for victim identification after the Great East Japan Earthquake. In this study, we evaluated the characteristics of output X-rays and measured air kermas of stray radiation from three battery-powered portable intraoral X-ray units.
Materials and Methods: The air kermas of stray radiation, generated from an IEC CT dosimetry head phantom and the X-ray units, which included DEXICO ADX4000, DEXICO ADX4000W, and DEXICO DX3000 （10DR Japan）, were measured using Pitman 37D and the 350cc ionization chamber attached （Pitman）.
Results: If an operator works in a sectioned area with a central angle of 180±60 degrees and a radius of 0.5m, the mean stray radiation was 0.353μGy for the ADX4000, 0.297μGy for the ADX4000W, and 0.288μGy for the DX3000 per 1mGy at the cone tip of each unit.
Discussion: In the event of a large-scale disaster, an operator would be taking many radiographs for victim identification each day. Therefore, this can be done by setting up a control area that ensures a sufficient distance from the radiation source, wearing a lead apron and using a protection board.
