[Determination of absorbed doses of radiation during lateral cephalometric radiography]

The aim of this study was to determine the absorbed doses of radiation in skin and deeper tissues as well as in critical organs, in vitro. For this purpose were used: a Siemens Orthoceph-10 cephalometric unit; a tissue equivalent Phantom head, type Rando; 43 thermoluminescencent dosimeters (T.L.D.), rare earth screens type, Siemens titan ZHS and Dupont Cronex-4 films 24 x 30 cm. Of the 43 T.L.D. 21 were places on the skin head, face and neck surface and 22 were places in deeper tissues and organs, and the exposure parameters were: 77 Kvp, 12 mA and 0.8 sec. The results of this study showed that: 1. doses on the left side towards focus were greater than the right side. 2. surface skin doses were ranged between 0.10 to 0.21 mGy. 3. Doses in deeper tissues or organs were varied and depended on the location and the consistency of tissue and were greater than the surface skin doses. Comparing our results with the results of other studies we can conclude that dose reduction to patient, can be achieved with use of rare earth screens in combination with fast speed film and the use of low exposure parameters.