The goal of this clinical trial is to determine the effectiveness of imiquimod in treating oral dysplasia in adult patients. Imiquimod 5% cream could be a safe and practical treatment for oral epithelial dysplasia (a precancerous change in the mouth). The main questions it aims to answer are:

1. Does imiquimod help to make the lesions smaller and make the abnormal cell changes less severe?
2. How can we make this treatment safer and more feasible?

Participants will apply topical imiquimod cream to treat the oral dysplasia and receive two follow-up biopsies after the treatment.

Inclusion Criteria:

• The patient has a biopsy-proven diagnosis of oral epithelial dysplasia.
• The patient is ineligible for or unwilling to undergo surgical or laser therapy.
• The patient is over 18 years old.
• The patient agrees to join the study and completes the informed consent process.

Exclusion Criteria:

• The patient has OL, and excisional surgical removal is indicated.
• The patient is immunocompromised.
• The patient is under 18 years old.
• The patient refused to join the study or did not complete the informed consent process.