Effect of muco-adhesive gel impregnated with curcumin and licorice on oral submucous fibrosis in buccal mucosa of rat after 16 weeks of treatment. 

a and b, Experimental group 2A at week 16 (scale bar=100 µm). c and d, Experimental group 2B at week 16 (scale bar=100 µm). In the 16th week, the experimental group 2A (a) showed moderate stage OSMF features i.e., varying thickness of epithelium with orthokeratosis (double black arrows), shortened rete pegs (black arrows), dilated and constricted vasculature, inflammatory infiltrate, dense collagen in connective tissue just below the epithelium (red arrows) and muscular atrophy (blue arrows) and (b) showed advanced stage OSMF features i.e., thin and atrophic epithelium with orthokeratosis (double black arrows), shallowed and absent rete pegs (black arrows), vascular constriction (green arrow), reduced cellularity, dense collagen in the form of sheets in connective tissue (red arrows) and muscular atrophy (blue arrows). In the 16th week, the experimental group 2B (c and d) showed early stage OSMF features i.e., increased epithelial thickness with orthokeratosis (double black arrows), short, long and broad rete pegs (black arrows), increased and dilated vasculature (green arrow), increased fibroblast, disordered collagen in lamina propria (red arrows) and muscular fibers interspersed between collagen bundles (blue arrows) (Stain: hematoxylin and eosin, Magnification: 10X).