Melanoma Pictures: Skin Changes and What to Look For About Moles Types, Warning Signs, Causes, and Prevention 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 Pigmented Lesions of the Oral Mucosa: Clinical Presentation, Histology, and Recommendations for Management American Journal of Clinical Dermatology Springer Nature Link Melanocytic Nevus: What Is It, Causes, Signs and Symptoms, and More Osmosis