You could make a some kind of dental trap like this.
http://saw.ugo.com/images/traps/the-jaw-trap.jpg
this 1 just so happens to rip your jaw apart, but its pretty complicated 2 make. just be creative. I had a saw room last year and you just have to give the room some dim lighting, and a bunch of blood stains.
you could also use power tools safely. ex: power drill with no bit, jigsaw with no blade. Good Luck on whatever you decide to do.