Labial melanotic macule Mystery behind labial and oral melanotic macules: Clinical, dermoscopic and pathological aspects of Laugier Hunziker syndrome Happy Wednesday! , In this video, a patients labial melanotic macule (a benign pigmented lesion) is being treated with liquid nitrogen. Labial melanotic macules are flat and asymmetrical with a Pigmented Lesions of the Oral Cavity Oral and Maxillofacial Surgery Clinics 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