I was watching Prison Break Season 1 with my wife recently and there is a scene where T-Bag is being beaten up by John Abruzzi's thugs. He get's pretty dinged up during the fight.
He is able to talk and plead without any indication that he has anything in his mouth.
After John releases him, he takes a razor blade out of his mouth and slits John's throat.
How is it really possible that he kept the razor in his mouth the whole time, especially without injury. I've read at Yahoo! Answers that it can be done, but in the story by the asker it appears that it was for a relatively short time.