MicroRNAs in gingival crevicular fluid as predictive biomarkers of orthodontic tooth movement: A systematic review

Objectives: MicroRNAs regulate gene expression involved in inflammation and bone remodeling, which are critical for orthodontic tooth movement. This systematic review aimed to evaluate the association between orthodontic tooth movement and changes in microRNA expression in gingival crevicular fluid. Methods: Electronic databases including PubMed, Scopus, Web of Science, Google Scholar, and ProQuest were searched. Eight eligible studies were included following predefined inclusion criteria. Methodological quality was assessed using the QUADAS-2 tool. Results: Significant upregulation of miRNA-7a-3p, miRNA-21-5p, miRNA-27, miRNA-29 family, miRNA-146, miRNA-155, and miRNA-221 was observed during orthodontic tooth movement, while miRNA-125b and miRNA-200 family showed reduced expression. Four studies demonstrated unclear risk of bias with high applicability relevance. Conclusions: Gingival crevicular fluid microRNAs demonstrate strong potential as non-invasive biomarkers for monitoring orthodontic tooth movement. Further standardized clinical studies are warranted.