Labial Lentigo (labial melanotic macule) Cancer Therapy Advisor Diffuse pigmentation of the oral mucosa Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics 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 Skin Path Histology Slides Pigmented Flashcards Quizlet Pigmented Lesions of the Oral Mucosa: Clinical Presentation, Histology, and Recommendations for Management