From the Loreta, the pilgrimage site in Prague, where I was recently a visitor: cherubs with an extracted tooth framing a painting of St. Apollonia.
Apollonia is a martyr and the patron saint of dentistry and toothache-sufferers. Before her death, she was tortured by having all of her teeth pulled out.
Side note: when looking for information on dental cherubs I found the website of one Dr. Cherubini, an orthodontist. I saw all the before and after photos and it looks like he does pretty impressive work.