Abstract
Background: Jaws spiral tomography and panoramic radiography have wide applications in dentistry, and the parotid gland is one
of the most sensitive organs of the head and neck.
Objectives: The aim of this study was to evaluate and compare the parotid-absorbed dose in spiral tomography and panoramic
radiographs using a thermoluminescent dosimeter.
Materials and Methods: A radiation analog dosimetry phantom was placed in a Cranex Tome radiograph device, and a parotid
absorbed dose was measured in both techniques. Thermoluminescent dosimeters were placed bilaterally in the parotid region
(on the tube side and the opposite side). Spiral tomography dosimetry was done for the upper and lower jaws in the anterior and
posterior regions. Each region contained four slices of 2 mm and four slices of 4 mm in thickness. The results were analyzed by a
Wilcoxon test.
Results: For the tube side parotid, the average absorbed doses in spiral tomography of the anterior and posterior parts of themaxilla
and mandible, with the 2 mm slice thickness, were 1.70/1.40 and 1.65/1.60 mGy, respectively. The average absorbed doses with the
4mm slices were 1.65/1.70 and 1.75/1.57 mGy, respectively. For the opposite parotid, the average absorbed dose in spiral tomography
of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice thickness, were 1.40/1.30 and 1.40/1.67 mGy,
respectively. The average absorbed doses with the 4mm slices were 1.50/1.66 and 1.40/1.50 mGy, respectively. The average absorbed
dose of the panoramic radiograph was 1.40 mGy.
Conclusions: There was no statistically significant difference in the parotid absorbed dose between spiral tomography and a
panoramic radiograph (P value = 0.18). The overall results of this study were similar to other studies.