A Rare Case of Oral Mucosal Pigmentation: Differential Diagnosis and Case Presentation JCDA Mucosal melanocytic macules Pigmented Lesions of the Oral Cavity Pocket Dentistry What Caused These Multiple Hyperpigmented Macules of the Mouth? ORAL MELANOTIC MACULE (OMM) (Also called focal melanosis labial melanotic macule) A benign, localized, flat pigmented lesion of the oral mucosa Caused by a focal increase in melanin production Differential diagnosis of an oral mucosal pigmented lesion: a case of essential melanosis