Micronucleus Formation in Oral Mucosal Cells Following Dental X-ray Exposure: A Systematic Review and Meta-analysis

Background Radiographic imaging is essential in dental diagnostics, yet concerns persist regarding its genotoxic impact. While digital advancements have reduced radiation doses, the effects of X-ray exposure on oral mucosal cells remain debated. This study systematically reviews and quantitatively analyzes the effects of X-ray exposure on micronucleus (MN) formation in oral epithelial cells, examining potential age-related variations. Methods A thorough literature review was performed across PubMed, Web of Science, EBSCO, and Scopus (updated to November 2024), adhering to PRISMA criteria. Eligible studies examined cytogenetic changes in oral epithelial cells after X-ray exposure in healthy individuals. Data extraction covered study design, imaging modality, radiation dose, micronucleus frequency, and statistical methods. Risk of bias was assessed using a modified EPHPP tool. A random-effects model synthesized micronucleus frequency changes, and Fisher’s Z-transformation analyzed age correlations. Results Eighteen studies met the inclusion criteria, with 16 centered on panoramic imaging and two examining a combination of CBCT and lateral cephalometric X-rays. Meta-analysis confirmed a significant increase in micronucleus frequency post-exposure (SMD = 0.30, 95% CI: 0.07–0.52, p = 0.01), indicating genotoxic effects. However, age showed a weak correlation with micronucleus formation (r = 0.149, 95% CI: -0.009 to 0.3, p = 0.065). Conclusions X-ray exposure induces measurable genotoxic damage in oral epithelial cells, though age-related effects remain inconclusive. Adhering to the ALARA principle is crucial to minimize unnecessary radiation. Future studies should employ larger cohorts and refined biomarkers to enhance risk assessment.