Dental diseases.

Dental diseases fall into four major categories: dental caries, or tooth decay; periodontal disease, including gingivitis and pyorrhea; Vincent’s infection, or trench mouth; and oral cancer. The first of these diseases was the largest contributor to tooth loss among people under thirty-five in the United States before the widespread fluoridation of drinking water was begun; it remains a major cause of tooth loss in much of the world. Periodontal disease in its two stages, gingivitis and pyorrhea, is the most widespread dental problem for people over thirty-five. Most people who suffer the loss of all of their teeth do so because of this condition. Vincent’s infection, which shares many characteristics with gingivitis, is bacterial. The infection flares up, is treated, and disappears, whereas gingivitis is more often a continuing condition that requires both persistent home treatment and specialized treatment. The most serious but least frequently occurring dental disease is oral cancer. It is the only dental disease commonly considered life-threatening, and there is a risk that it may spread to other parts of the body.