Our precious daughter, Megan had an expander put in her mouth to, well... expand her mouth :)
In order to do this, it requires us (as parents) to stick a metal "key" in her mouth and crank it a full turn 3x a day. An adult friend of ours just had his removed early because he couldn't "handle the pain."
Megan, on the other hand - literally would run to the couch, throw her head back and say, "I'm ready to be cranked!"
Here is a little bit of her life from her side of it...Peace!