This Star-Journal photo accompanied the story. The caption is less than satisfying:

"WHERE DENTISTRY STUDENTS GET PRACTICAL EXPERIENCE

Under supervision of instructors, future dentists treat young patients on 'children's day.' "

What exactly was "children's day"? Where did the children come from? Which procedures were being taught this day? Were there any female students? And who's the cute kid in the foreground?

New 'U' Dental Dean
Cites Sugar as No. 1
Enemy of Good Teeth

By BEN HOLSTROM Star-Journal Staff Writer Human teeth are breaking down. More people have decayed teeth today than 10 years ago. But dental scientists are on the verge of discoveries which may halt the destruction and give the next generation better teeth than ours. So says Professor William H. Crawford, new dean of University of Minnesota school of dentistry – one of the top dental schools in the country. Crawford was graduated from Minnesota in 1923. He returned to Minneapolis July 1 from the University of Indiana, where he had been head of the dentistry school for five years. Professor E. A. Hooton, famous Harvard university anthropologist, says civilization is raising havoc with teeth. He asserts they have become the foci of infections which threaten to undermine the health of the whole human species. Crawford agrees that tooth decay is becoming more and more serious. The process is going on without interruption, because a study of the teeth of University of Minnesota freshmen from 1929 to 1939 disclosed a 5.5 per cent increase in decay. He also agrees with the Harvard savant that dentistry schools have too often been backward in their own field while too many dentists have been content with being tooth carpenters rather than scientists. But, says the new dean, all that is changing. Dental scientists are no longer baffled by what causes tooth decay. They are pretty sure the culprit is sugar. Crawford is so confident of this finding that he will undertake to stop tooth decay in any child by the simple expedient of putting it on a sugar-free diet for 10 days or two weeks. Decay seems to be caused by excretions of bacteria, which live on fermented sugar. Chief of these is the lactobacillus acidophilus. When the sugar is removed, the organism dies. Even after the child is put back on a moderate sugar diet, Crawford said, the bacteria do not return in large numbers. He blames increase in tooth decay among youngsters of today on the fact that they get too much sugar in the form of candy and pop. Dental scientists are now hot on the trail of something else which seems to have a lot to do with good or bad teeth. This is the chemical fluorine. It is used to etch glass. It is also employed as an insecticide. It also has the property, when it enters into the building of teeth, of making them resistant to decay. The United States public health service, studying results of a national survey on the incidence of tooth decay, found one town in Illinois where the incidence was very much lower than in nearby towns. Investigation showed there was fluorine in that town's water supply. The story wasn't all good, because teeth of some of the people in the town were found to be very badly pitted, although sound. The answer seemed to be that too much fluorine prevents the enamel from forming. That was in 1937. Almost at the same time a University of Minnesota bio-chemist, Dr. W.D. Armstrong, was completing an experiment which led to the same conclusion. Investigation the composition of sound and decayed teeth, he found that the sound teeth contained minute quantities of fluorine. Investigation of the effects of fluorine on teeth has barely begun, Crawford said. It is being carried on at the dentistry school every day. Dental scientists are enthusiastic about it. Several towns – Grand Rapids, Mich., among them – have started putting fluorine in their drinking water at the rate of one part per million, which seems to be the right dose to preserve teeth without attacking them. Another experiment with fluorine is going on now in Minnesota. For the past two years, a solution of sodium fluoride has been periodically applied to the teeth of the children in North Mankato, Arlington and St. Louis Park schools under direction of the dentistry school. Half of the teeth of each child have been treated and other half left untreated. The observable result so far has been a 41 per cent reduction in decay in the treated teeth. One of the factors cited by Hooton for the deterioration of our teeth is that the jaw is undergoing evolutionary degeneration. Both the mandible and maxillary are shrinking while the teeth aren't, at least to the same degree, so that a man's teeth today are often too big and too numerous for his jaws, and erupt in every which way. As mankind became daintier and daintier in his habits the jaw shrank. In modern times, this degenerative process has brought into being the science of orthodontics, the technique of straightening crooked teeth – another way modern dentistry has found to combat nature. Modern man loses about half his teeth from the decay and the other half from diseases of the tissues in which the teeth are imbedded, Crawford says. The whole field of these diseases is yielding slowly to the work of the dental scientists, although they still have a long way to go. Dental practice is changing so rapidly that Crawford thinks it imperative that a modern dental school should have refresher courses for practicing dentists and hopes to establish such courses at Minnesota. He also believes dentists should read more about discoveries in their own field in order to keep abreast of the times.

A 1940s dental office: No masks, no gloves, no gas, but the look of dread is familiar to anyone who has endured dental work without painkillers. (Image courtesy mnhs.org)

More evidence that no one looks good in a dental smock: A dentist examines the teeth of a woman at the State Fair in 1947. (Minneapolis Tribune photo)

Open wide, open wide, open wide: Children at St. Paul's Como Park School have their teeth examined in this 1930s photo. (Image courtesy mnhs.org)

Ben Welter, Star Tribune

Where the magic happened: The main clinic at the University of Minnesota's school of dentistry in 1932. (Image courtesy mnhs.org)