[Pigmentation and pigmented lesions of the gingival mucosa].

The pigmentation is the physiological or pathological accumulation of a pigment in a tissue. Physiological pigmentation in gingiva which is a part of masticatory mucous membranes depends on the activity of the melanocytes. These non keratinocytic cells include the melanosoma where an endogenous pigment, the melanin, is synthesized. Quantitative or qualitative disruption of mucous pigmentation leads to the apparition of pigmented lesions. When melanocytes are directly concerned, the lesions can be of intrinsic origin, such as oral mucosa melanoma, the nevus, pigmented oral lichen planus etc. Pigmented lesions can be also of extrinsic origin caused by medicaments, dental materials, tobacco etc. In this article, gingival pigmentations are described to allow practitioner to elaborate a differential and positive diagnosis of gingival pigmented lesions and to facilitate an early detection of these lesions particularly the gingival melanoma.