Figure 1: Pattern of overall innervation in noninflamed oral mucosa (OM), reticular type of oral lichen planus (OLP-R) and erosive type of oral lichen planus (OLP-E). Avidin-biotin peroxidase complex (ABC) staining of PGP 9.5 amplified with glucose oxidase-nickel ammonium sulfated methods in all panels (a-h), magnification ×200. a, c, e, f represent the negative control (omitting primary antibody) from adjacent sections of PGP 9.5-positive nerve fibers. No PGP 9.5-positive nerve fibers are seen in any control sections. B and D show the PGP 9.5-positive nerve fibers in noninflamed oral mucosa. Innervation in noninflamed oral mucosa is distributed completely in the deep lamina propria surrounding the blood vessels (arrows) (d). No subepithelial neural network is found (b). OLP-R (f) and OLP-E (h) show a dense subepithelial neural network in OLP (arrows). Nerve fibers are concentrated close to the basement membrane. e: Epithelium; c: Connective tissue