Background: X-rays are potential mutagenic agents that can cause both the gene mutations and chromosomal aberrations. Aims: In this study, the micronucleus (MN) test and the comet assay methods are implemented in order to observe the damage that can occur in the cell nucleus and in the structure of DNA of the patients who underwent a panoramic examination. Methods and Materials: In our study, buccal mucosa swabs were obtained just before the radiography and 2 weeks after the radiography from 30 volunteer patients who had to take radiographs due to dental diagnosis. Changes in the nuclei of 1,000 cells of each swab sample had been counted under a light microscope and recorded. Besides, 100 cells of each other swab samples were analyzed by the comet assay. Comet assay parameters namely tail length and percentage of DNA in tail, which indicate the level of DNA damage were analyzed and compared in both groups. Statistical analysis was performed by using the Statistical Package for the Social Sciences (Version 21). Results: In our study, the results of percentage of DNA in tail and tail length before and after X-ray exposure were statistically significant (P < 0.001). Likewise, increase in the MN frequency observed in buccal mucosa cells after X-ray exposure was found significant (P < 0.001). Conclusions: As a result, panoramic radiographs taken during dental diagnosis and treatment cause cytotoxicity and DNA damage in oral mucosal cells. Panoramic radiographs should be applied only when necessary, using an accurate radiographic technique and radioprotection criteria.