The salivary secretions in health and disease.

The potential usefulness of analysis of the salivary secretions in diagnosis and prognosis is beginning to be explored in depth. The preliminary work already undertaken indicates that modern methods applied to this secretion may provide information that is different from that obtained in other body fluids. Saliva is collected at the point of its manufacture and, therefore, is unaffected by collection or storage in the body. It is the product both of protein synthesis within the glands and of most of the known water and electrolyte exchange mechanisms. Salivary composition is affected by both autonomic and hormonal stimuli. As the specific influence of each of these factors is better understood, studies of this fluid will provide important clues to the understanding of disease and the evaluation of therapy. There are few places in the body where it is possible directly, utilizing a non-invasive technique, to examine the product of a large number of important biological processes. It is obvious that careful handling of collection and analytic techniques are essential if these secretions are to be utilized. Future investigations in clinical situations should take full advantage of the strong base of knowledge of the physiology of these glands. Development of this field depends on careful clinical investigations designed to make full use of our current knowledge.