Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review 05 May 03 Eng 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 Mystery behind labial and oral melanotic macules: Clinical, dermoscopic and pathological aspects of Laugier Hunziker syndrome COM March 2009 Diagnosis UW School of Dentistry