"An exact duplicate, its core shaped most exquisitely like a nerve. It'll escape the usual detectors, even a fast scanning. But if you bite down hard on it, the cover crushes. Then, when you expel your breath sharply, you fill the air around you with a poison gas..."

Cool remoteness spread upward from Leto's jaw, across his cheeks. The shadowy, hall narrowed to a pinpoint with Yueh's purple lips centered in it.

"Remember the tooth!" Yueh hissed. "The tooth!"

From Dune by Frank Herbert


She had to call everybody she knew. After the tooth fairy left her money, she's trying to eat carrots and crunchy things so that more of them can fall out.