Tooth Island is a location that only appears in the episode "The Whole Tooth."
Tooth Island slightly resembles Bikini Atoll, but it has more trees and bushes. On the island, it has calcium pools, pink gum trees, and floss vines.
Tooth Island is a place where baby teeth go to after being extracted. The baby teeth are sent there by a ship called the Tooth Ferry. Once they are on the island, they swim in the calcium pools, sleep in the gum trees, and swing on the floss vines so they'd never worry about cavities.