Objective:The aim of this study was to investigate the features of mast cell subtypes and relationship between mast cells and pathogenesis of oral lichen planus.Methods:Mast cells in the tissue of oral lichen planuswere stainedwithAlcian blue /safranine in order to demonstrate mature and immature mast cells, and the constituent ratio of these two subtypes was calculated. After- wards, LUZEX-F image pattern analysis system was applied to demonstrate the size of these two subtypes and their morphological features.Results:The constituent ratio of mature and immature types of mast cells in the tissue of oral lichen planus was signifi- cantly different from that in the normal tissue (P
