Pigmented Oral Lesions: Clues to Identifying the Potentially Malignant Consultant360 Dark Spot on Lip: Harmless or Serious? What to Check First La Bouche Parfaite Pigmented Lesions of the Oral Mucosa Pocket Dentistry COM April 2005 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