Evidence of genotoxicity and cytotoxicity of X-rays in the oral mucosa epithelium of adults subjected to cone beam CT

Abstract

Objectives: To assess cytological evidence of genotoxicity and cytotoxicity of X-rays in oral exfoliated cells of adults subjected to partial and total cone beam CT (CBCT) (stitching module) by means of micronuclei frequency, associated with counting of degenerative nuclear alterations (pyknosis, karyolysis, karyorrhexis, buds and broken eggs), besides comparing the partial and total CBCT (stitching module) in search of possible differences in the nature and/or intensity of the effects.

Methods: 29 adults who were referred to total or partial CBCT were selected. All CBCT were performed with a Carestream CS 9000 3D scanner (Carestream Health Inc., Rochester, NY). Material collection was done immediately before CBCT and 10 days later, by scraping the left and right cheek mucosa with a plastic spatula. Statistical analysis was performed using the Wilcoxon test (paired data), at a significance level of 5%.

Results: The statistically significant difference was noted in the frequency of micronucleated cells for both partial and total acquisition (p = 0.008 and p < 0.001, respectively). Regarding to cytotoxicity, there was a statistically significant difference for both partial and total acquisition (p < 0.001 and p < 0.001, respectively).

Conclusions: The partial and total CBCT seems to offer risks of inducing genetic damage. In addition both forms of CBCT acquisition have promoted the induction of cytotoxic nuclear alterations.

Keywords: cone-beam computed tomography; micronucleus test; mouth mucosa.

Figures

Figure 1.

Nuclear alterations observed in cytological smears stained by the Papanicolaou technique of patients submitted to ionizing radiation during performance cone beam CT. (a, b) micronucleus (straight arrows); (c, d) pyknosis (dotted straight arrows); (e, f) karyolysis (#); (g, h) karyorrhexis (*); (i, j) broken eggs (curved arrows); (k, l) nuclear buds (dotted curved arrows).

Figure 2.

Frequency of micronucleated cells observed in the cytologic smears of jugal mucosa of patients submitted to cone beam CT partial (a) and total (b). Data expressed as median (min to max). *p < 0.01; statistically significant difference between groups (Wilcoxon test).

Figure 3.

Frequency of cells with other nuclear alterations (pyknosis, karyolysis, karyorrhexis, buds and broken eggs) observed in the cytologic smears of the jugal mucosa of patients submitted to cone beam CT partial (a) and total (b). Data expressed as median (min to max). **p < 0.001; statistically significant difference between groups (Wilcoxon test).