Effect of orthodontic fixed appliances on epithelial cells of lower lip oral mucosa during orthodontic treatment

Background and aim: The aim of this study was to find out influence of the orthodontic devices on the oral epithelial cells. Materials and methods: Cells of lower lip oral mucosa from 32 orthodontic patients were collected by exfoliative cytology in three times: Day 0 (just before appliance placement), and 14 and 60 days after appliance insertion. Nuclear (NA) and cytoplasmic (CA) areas, NA/CA ratio, cell morphology, and cellularity of smears were analyzed by using cytologic and cytomorphometric methods. Results: The NA of the cells adjacent to orthodontic devices diminished after appliance placement, and reached to its lower level in day 60 (p = 0.000). Investigated epithelial cells showed insignificant changes in CA. Type II inflammatory smears, according to Papanicolau, increased insignificantly after the treatment initiation. Superficial epithelial cells, were predominant cell type in day 14 and 60 (p= 0.002).. Conclusion: Orthodontic appliances cause reduction in NA and induce epithelial hyperkeratosis in lower lip mucosa.