[Melanocytes in the epithelium of the gingival mucosa in different conditions of edentia].

Gingival crest melanocytes were examined in partial and total edentulates (with and without prostheses). Where the epithelium showed signs of epidermisation, the cells displayed their normal form and melanogenetic activity. In the presence of involution (acanthosis, reduction of the surface layers, smallcell infiltration), they withdrew their typical cytoplasmic expansion, while the Dopa reaction revealed poor thyrosinase activity. It is felt that these patterns confirm the epithelio-melanocyte symbiosis theory put forward by Quevedo et al. One total edentulate with a mucosally supported prosthesis displayed Dopa-positive dendritic cells on the gingival corium and tunica propria. These are seen as true melanocytes that had migrated from the epithelium.