Dentistry and Medicine: Pigmentation and Discoloration of Oral and Facial Tissues Melanotic macule MEDizzy Oral Malignant Melanoma Oral Cancer Foundation Information and Resources about Oral Head and Neck Cancer 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