The device you're wearing is hooked into your upper and lower jaws.
6 seconds sound clip from the Saw (2004) movie soundboard.
You can hear this line at 00:24:58 in the Blu-ray version of the movie.
Quote context
[...]
- She's the only one who made it.
- Amanda... In your own time, tell me the first thing you remember.
- I woke up. All I could taste was blood. And metal.
- Hello, Amanda. You don't know me, but I know you.
- I want to play a game. Here's what happens if you lose.
- The device you're wearing is hooked into your upper and lower jaws.
- When the timer on the back goes off, your mouth will be permanently ripped open.
- Think of it like a reverse bear trap.
- There's only one key to open the device. It's in the stomach of your dead cellmate.
- Look around, Amanda. Know that I'm not lying.
[...]