The oral mucosa as a mirror of general health or disease

There is a close relationship between general health/disease and oral mucosal reactions. Many diseases show unspecific or specific changes which may evolve throughout the course of the disease but the mucosal reaction may also constitute the initial clinical sign of the disease. Among the broad spectrum of conditions/diseases, three have been selected for this review--HIV/AIDS, Sjögren's syndrome and lichen planus. They illustrate how general disease may be mirrored in the oral mucosa. An attempt has been made to describe the scientific frontiers and to select pertinent key or review articles or books from among the huge amount of literature published in recent years.