Head Face Med 2014 Mar 24, 10:8
Feller L, Masilana A, Khammissa RAG, Altini M, Jadwat Y, Lemmer J.
The presence of melanocytes in the oral epithelium is a well-established fact, but their
physiological functions are not well defined. Melanin provides protection from environmental
stressors such as ultraviolet radiation and reactive oxygen species; and melanocytes function as stress-sensors having the capacity both to react to and to produce a variety of
microenvironmental cytokines and growth factors, modulating immune, inflammatory and
antibacterial responses. Melanocytes also act as neuroendocrine cells producing local
neurotransmitters including acetylcholine, catecholamines and opioids, and hormones of the
melanocortin system such as proopiomelanocortin, adrenocorticotropic hormone and α-
melanocyte stimulating hormone, that participate in intracellular and in intercellular signalling
pathways, thus contributing to tissue homeostasis.There is a wide range of normal variation in melanin pigmentation of the oral mucosa. In general, darker skinned persons more frequently have oral melanin pigmentation than light-skinned persons. Variations in oral physiological pigmentation are genetically determined unless associated with some underlying disease. In this article, we discuss some aspects of the biophysiology of oral melanocytes, of the functions of melanin, and of physiological oral pigmentation.