COM August 2004 Diagnosis UW School of Dentistry 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 Diagnosis of oral pigmentations and malignant transformations ScienceDirect 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 Cavity Oral and Maxillofacial Surgery Clinics