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 Oral Malignant Melanoma Oral Cancer Foundation Information and Resources about Oral Head and Neck Cancer Oral Malignant Melanoma Oral Cancer Foundation Information and Resources about Oral Head and Neck Cancer Oral Melanotic Macule: Symptoms and Treatment Skinsight