Sensitivity and Specificity of Serum and Salivary CYFRA21-1 in the Detection of Malignant Transformation in Oral Potentially Malignant Mucosal Lesions (Diagnostic Accuracy Study)

Inclusion Criteria: participants will be divided into 3 groups: * Group I: patients suffering from oral potentially malignant lesions (PML) as defined by World Health Organization. * Group II: patients suffering from diagnosed oral malignant lesions * Group III: healthy subjects who are systemically free, non-smokers, and not suffering from any oral mucosal lesions. Exclusion Criteria: * Subjects taking any drugs inducing any changes that could affect the salivary flow. * Pregnant females. * Subjects have any allergies, infectious diseases or active dental abscesses during one month before saliva sampling. * Patients receiving any drugs related to the oral lesions in the past 6 month prior to sample collection.