title: Extrinsic discoloration of the oral mucosa.
mesh_terms: D006801:Humans; D009059:Mouth Diseases / Q000139:chemically induced; D009061:Mouth Mucosa / Q000187:drug effects; D010859:Pigmentation Disorders / Q000139:chemically induced*; D014060:Tongue Diseases / Q000139:chemically induced / Q000209:etiology