Because they have
three sets of TEETH and will
take a bite out of anything?
Breaking Bad Season 2, Episode 5
You're gonna brush
your TEETH on my couch?
The Big Bang Theory Season 7, Episode 10
I'm gonna go brush my TEETH;
it might take a while.
The Big Bang Theory Season 5, Episode 18
Swords or lances, TEETH, nails -
Game of Thrones Season 1, Episode 9
...to pick food from my TEETH
and massage my gums.
The Big Bang Theory Season 4, Episode 6