Eat your heart out, tooth fairy. According to the informal research of the author, the world is full of other, equally fascinating myths and traditions about what happens, or should be done, when those milk choppers part company with childish gums. If you come from Chile or Costa Rica, your parents will have the tooth made into a charm. If you're Venezuelan, you put the tooth under your pillow and hope that a mouse brings you money. (Oddly enough, mice, milk teeth, and money are associated all over the world.) Playful illustrations by G. Brian Karas include a world map, plus lots of fun depictions of the world's dentally challenged junior inhabitants. (Ages 4 to 8) --Richard Farr