RESUMO
Context: Ionizing radiation is a well-known carcinogen in humans. Chromosomal aberrations and formation of micronuclei in cell cytoplasm are early biological evidence of carcinogenesis. Aims: This study was undertaken to assess the genotoxic effect of panoramic radiography in the buccal epithelial cells. Materials and Methods: The study included 60 healthy individuals (median age 23.5 years; age range 12-65 years) who underwent panoramic radiographic examination. Exfoliated buccal epithelial cells were obtained immediately before and 10 days after radiation exposure. The cells were stained with Giemsa and evaluated for micronuclei by scoring 1000 cells per sample. Statistical analysis used: The paired 't ' test was used to find out the significance of difference in the number of micronuclei before and after x-ray exposure. The Karl Pearson correlation coefficient was used to find out the correlation between age and micronucleated cell frequencies and number of micronucleus per 1000 cells. The ANOVA test was used to find out if there were significant differences in micronucleated cell frequencies between different age-groups. Student's unpaired 't' test was used to find out the significance of difference in micronucleated cell frequencies and number of micronucleus per 1000 cells between genders. Results: The paired 't' test showed that micronucleated cell frequencies (P = 0.02) and number of micronucleus per 1000 cells (P = 0.047) were significantly higher after radiographic exposure. The mean number of micronucleated cells before and after radiation exposure were 0.48 ± 0.14 and 0.51 ± 0.15, respectively. There was statistically significant increase in the frequency of micronuclei in buccal epithelial cells after exposure to panoramic radiography. The correlation of micronucleus frequency with age and gender was statistically nonsignificant. Conclusions: The results indicate that panoramic radiography may induce genotoxic effects in buccal epithelial cells. Considering this risk, panoramic radiography should be used cautiously.