Nm. Tole et al., RADIATION-DOSE AS A FACTOR IN THE CHOICE OF ROUTINE PREOPERATIVE DENTAL RADIOGRAPHS, East African medical journal, 70(5), 1993, pp. 297-301
Radiation doses received by patients during dental x-ray examinations
were measured in 95 patients referred to the X-ray Department of the T
eaching Dental Hospital, University of Nairobi. The mean skin dose for
single periapical films was 5.% milligray (596 millirads) with the bi
tewing view recording a mean dose of 5.57 milligray (mGy). During a 14
-film full-mouth periapical survey, mean doses ranged from 10.3-16.2 m
Gy for the upper jaw and 10.1-13.5 mGy for the lower jaw, respectively
, depending on the region of dentition. In these full-mouth examinatio
ns, the distribution of skin dose over different parts of the dentitio
n showed a characteristic pattern which may be explained by the overla
p of radiation fields in the aggregated series of exposure. Orthopanto
mography recorded lower mean skin doses of 3.26 mGy in the molar regio
n and 2.67 mGy at the posterior midline at the level of the 2nd cervic
al vertebra. The relative merits of intra-oral radiography versus orth
opantomography are discussed, with radiation dosage as one of the fact
ors to be considered. Some observations are made on measures to reduce
patient dose.