The dentist was called away from the dinner table to take an urgent phone 
call. It was Mr. Tuckerman, explaining that young Junior had gotten 
himself into quite a fix.

"See, he was kissing his girlfriend, and when my wife and I came back from 
the movies we found them stuck together."

"I'll come right over, Mr. Tuckerman," said the dentist calmly, "and don't 
worry about a thing. I have to unlock teenagers' braces all the time."

Mr. Tuckerman whispered, "Yes, but from an IUD?"