Melanotic macule MEDizzy 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 Labial melanotic macule. B). Increased numbers of me lanocytes along Download Scientific Diagram Pigmented Oral Lesions: Clues to Identifying the Potentially Malignant Consultant360 Oral melanoacanthoma and oral melanotic macule: a report of 8 cases, review of the literature, and immunohistochemical analysis