A button handed out to children for their participation in the long-running Baby Tooth Survey begun in 1958 by the Greater St. Louis Citizens’ Committee for Nuclear Information (CNI). The survey was an effort to monitor levels of the isotope Strontium-90, which was entering the food chain following atmospheric nuclear detonations.
The survey required the the participation of every school in the St. Louis area and was boosted by a typically anodyne Atomic Age publicity blitz. From a 1964 report:
"During the weeks of the semi-annual Tooth Round-ups, public service time is given generously by radio and television stations to publicize the needs of the Survey. Mayor Raymond Tucker has proclaimed Tooth Survey Week. Last December the Veiled Prophet queen, St. Louis’ traditional reigning beauty, celebrated the Survey’s fifth birthday with a party at Children’s Hospital. A large model of a tooth (with a child inside) gives out forms in department stores. And, most important, dentists are reminded by letter and at conventions how helpful it will be if they make the forms available in their offices. So well known has BTS become that letters from children, addressed simply “Tooth Fairy, St. Louis,” reach their destination at the CNI office."