introduction: oral lichen planus (olp) is a common mucocutanous disorder with unknown etiology. while current data suggest that oral lichen planus is a cell-mediated autoimmune disease, it might be associated to s+100, cd+4 and cd+8 cells. because of differential diagnosis of olp and oral lichenoid lesion (oll) is usually difficult this study was designed to compare any probable immunohistochem...