Trade signs have descended from a lineage that can be traced back to ancient Greek and Roman cultures. What began as a necessity, when literacy was not widespread, became a tradition, and instantly recognizable iconic images continued to advertise businesses through the turn of the twentieth century. Some of the earliest signs, such as the free-standing tavern signs often stationed near the road, were flat and two-sided, but increasingly they were three-dimensional carvings hung off the facades of buildings to catch the eyes of passersby. These carved signs often were oversized versions of everyday objects immediately associated with the particular trades they advertised. Their size helped to draw attention, especially as towns became congested with competing businesses.

Many of the early signs established symbols that remain with us to the present time, such as the tooth that advertised the services of a dentist. Several examples of carved molars survive, and most date to the second half of the nineteenth century. Before that time, surgery, obstetrics, and dentistry were all often part of a country doctor's duties. Until dental surgery became a specialty, physicians pulled teeth as part of their regular practice.

Stacy C. Hollander, "Tooth Trade Sign," in American Anthem: Masterworks from the American Folk Art Museum (New York: Harry N. Abrams in association with American Folk Art Museum, 2001), 335.