Labial melanotic macule. B). Increased numbers of me lanocytes along Download Scientific Diagram Melanotic macule MEDizzy 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 Does anyone know what this black mark on my lip is? Started last August so it's I've had it nearly a year, was living in Spain at the time for 6 months