ABSTRACT
There is an ancient axiom that ‘‘all trouble comes from the mouth, but not all troubles leave.’’ True to that axiom, numerous disfiguring developmental abnormalities, infections, and neoplasms take seed and remain in the oral and perioral tissues. Not only does the mouth have its own unique diseases, but also it often provides clues to wider problems. For example, failure of the immune system may initially be announced by oral candidiasis or hairy leukoplakia. Oral ulcers may signal inflammatory bowel disease before it is discovered in the bowel. The majority of substances that enter the body pass through the mouth, exposing the oral cavity to various elements such as cigarette smoke, which makes contact with oral tissues during inhalation and exhalation. Hematopoietic diseases such as leukemia, lymphoma, and myeloma and a host of venereal diseases are often initially evident in oral tissues. Thus, this chapter is devoted to benign, but not always harmless, lesions of this complicated structure.
