Unfortunately the great majority of parents rarely think of their children's teeth until too late to preserve them intact. Even among families where the rule of brushing the teeth twice daily prevails, regular dental examination is often not required. Doctors and dentists themselves have not been trained to realize that the teeth are a most dangerous source of infection when unclean. Does your dentist insist upon removing tartar and food particles beyond your reach, upon polishing and cleansing, or does he regard these as vanity touches, to be omitted if you are in a hurry? [Illustration: INDUSTRIAL HANDICAPS DISCOVERED AT SCHOOL] Physicians send tuberculosis patients to hospitals or camps without correcting the mouth conditions that make it impossible for the patient to eat or swallow without infecting himself. Tonics are given to women whose teeth are breeding and harboring disease germs that tear down vitality. Nurses watch their suffering patients and do the heavier tasks heroically, but are not trained to teach the simple truths about dental hygiene. The far-reaching results of neglect of teeth will not be understood until greater emphasis is placed on the bacteriology, the economics, the sociology, and the aesthetics of clean, sound teeth. Whether or not there is at present a tendency to exaggerate the importance of sound teeth, there is no difference of opinion as to the fact that the teeth harbor virulent germs, that the high temperature of the mouth favors germ propagation, that the twenty to thirty square inches of surface constantly open to bacterial infection offer an extensive breeding ground, and that the formation of the teeth invites the lodgment of germs and of particles of food injurious both to teeth and to other organs. By scraping the teeth with the finger nail and noticing the odor you can convince yourself of the presence of decomposing organic matter not healthful to be carried into the stomach. By applying a little iodine and then washing it off with water, your teeth may show stains. These stains are called gelatinous plaques, which are transparent and invisible to the naked eye except when colored by iodine. These plaques protect the germs, which ferment and create the acid which destroys tooth structure. Their formation can be prevented by vigorous brushing and by eating hard food.