Trying to open a hermetically sealed container with teeth is not the best idea. In fact, it's a really, really, REALLY bad idea.
First of all, hermetic seals are designed to be, you know, hermetic. Like, they don't let air in or out. That's the whole point.
You're essentially trying to force your teeth into a situation where they're going to get stuck. Like, really stuck. As in, "you'll-never-be-able-to-get-your-teeth-out-of-there" stuck.
But hey, if you're still determined to try, be my guest! We've got some fun links for you to click on: