Health and appearance of gingiva are important parts of a smile. The color of the gingiva is various among different individuals and it is thought to be associated with cutaneous pigmentation. It varies from light to dark brown or black. The skin tone, texture and color differ in various races and regions. The gingival color depends primarily upon the number and size of vasculature, epithelial thickness, degree of keratinization and pigments within the gingival epithelium. Melanin, carotene, reduced haemoglobin and oxy-haemoglobin are the prime pigments contributing to the normal color of the oral mucosa.
Gingival pigmentation is presented as a diffuse deep purplish discoloration or as irregularly shaped brown and light brown or black patches, striae or strands. It results from melanin granules, which are produced by melanoblasts. Melanin, a non-hemoglobin–derived brown pigment, is the most common of the endogenous pigments and is produced by melanocytes present in the basal and suprabasal cell layers of the epithelium.
Melanin pigmentation appears as early as 3 h after birth in the oral tissues and in some cases is the only sign of pigmentation on the body. It is generally agreed that pigmented areas are present only when melanin granules synthesized by melanocytes are transferred to the keratinocytes. This close relationship is known as the ‘epidermal-melanin unit’.Causes
The gingiva is considered the most frequently pigmented tissue in the oral cavity. Gingival pigmentation is a discoloration of the gingiva due to a variety of lesions and conditions associated with several endogenous and exogenous etiologic features. It may range from physiologic reasons (e.g. racial pigmentation) to mani- festations of systemic illnesses (e.g. Addison's disease) to malignant neoplasms (e.g. melanoma and Kaposi's sarcoma).