Thirty patients will be recruited from the outpatient clinic of the faculty of dentistry.fifteen systemically healthy individuals with normal mucosa and fifteen atrophic/erosive oral lichen planus patients. Oral lichen planus patients will be treated with a topical steroid and miR-155 and IL-10 will be assessed in saliva before and after 4 weeks of topical steroids use

Inclusion Criteria:

• Patients clinically and histopathologically diagnosed as having atrophic/erosive OLP.
• Patients free from any other oral lesions
• cooperative patients who agrees to take the supplied medications.
• Patients who are systemically healthy

Exclusion Criteria:

• Patients suffering from any systemic disease.
• Treatment with any systemic treatment such as systemic steroids, other immunosuppressive drugs or non-steroidal anti-inflammatory drugs at least eight weeks.
• Treatment with any oral topical medications for at least four weeks prior to the study.
• Pregnant and lactating women.

Patients with atrophic/erosive oral lichen planus