Evaluation of Relationship between Exposure Parameters and Maxillofacial Bone Quality with Salivary Glands Absorbed Dose in Cone Beam Computed Tomography Imaging

Abstract

AIM: The purpose of this study was to evaluate the protective effect of jaw bone on the dose of salivary glands and its relationship with radiation conditions. MATERIALS AND METHODS: In this cross-sectional study, seven dried human skulls were used. In each mandible, six dosimeters were placed in six salivary gland regions numbered in visible light absorbent envelopes. Cone beam computed tomography (CBCT) images were taken from each mandible with a constant kV of 90 and mA varied from 6, 8, and 10. The absorbed dose was calculated using SOLAR 2A. The bone quality of each of the six areas was obtained using densitometry tool in On Demand software. Finally, the results were analyzed using Statistical Package for the Social Sciences (SPSS) software version 23 with covariance and Tukey tests (alpha = 0.05). RESULTS: The results of covariance analysis and Tukey test indicated that the sublingual salivary gland had the highest absorption dose. Meanwhile, the results of the analysis showed that the absorption rate of the glands increased by increasing the radiation conditions from 6 to 8 and increasing from 8 to 10 mA (p < 0.001). The results of Pearson analysis showed an inverse relationship between absorbed dose and bone quality (r = -0.327) (p < 0.001). CONCLUSION: The results of this study showed that the absorption rate of salivary glands will increase with increasing radiation conditions, while increasing the quality of mandibular bone, the absorption dose will decrease. CLINICAL SIGNIFICANCE: The clinical significance is to reduce patient's absorbed dose in order to decrease the risk of mutation and cancer formation.