Pigmented Lesions of the Oral Cavity Pocket Dentistry This is a picosecond laser treatment of labial melanotic macules on the gingiva. Note the green flashes of the 532 nm laser as well as the immediate tissue whitening of the treated area. This Oral Malignant Melanoma Oral Cancer Foundation Information and Resources about Oral Head and Neck Cancer Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review Gum Hyperpigmentation: When to Seek Help?