Date of Award

Spring 1950

Document Type



Life & Environmental Sciences


There are no regions of the body which normally support a more abundant and varied population of microbes than the mouth and throat. The moist warm mucous membrane furnishes excellent conditions for the life of all types of microbes. Bacteria thrive especially well in remnants of food, and in debris of dead epithelial cells, about the teeth. The peculiar anatomy of the mouth cavity and throat affords sheltered living places for numerous types of anaerobic as well as aerobic bacteria. Anaerobic organisms are especially abundant about the gum margins, in crevices between the teeth, and in the deep folds, or crypts, in the surface of the tonsils.

A list of the microbes which have been cultivated at one time or another from the human mouth reads like a catalogue of all the main group of microorganisms. Numerous species of cocci, bacilli, and spirilla, and also several kinds of higher bacteria, spirochetes, yeasts, and mold-like organisms, as well as amebae and other protozoa, may be present.

In the mouth of nearly every person there are places where the gums are not anatomically perfect--they do not meet the teeth with a knife edge, but instead, the gum margin is blunted and easily loosened from the teeth. If an inoculating needle is passed along this blunted margin, or forced between the gum and the tooth, and if the material thus secured is examined under the microscope, a seething mass of bacteria is revealed.

The number of these bacteria in the mouth depends upon the degree of cleanliness of the teeth, as well as upon the anatomical condition of the gum margin. A similar flora is present in the tonsillar crypts. It is important to realize that these very organisms in the normal mouth are often found associated with disease, such as ulceration in the mouth or throat and abscesses about the head and neck. The origin of lung abscesses, particularly those following an operation in which ether anesthesia was used, may often be traced to bacteria from the mouth. These facts make clear the importance of good mouth hygiene.