These are one of the funniest kind of jokes because the Medical profession is otherwise a serious profession.
During Zia's rule, a gentleman travelled all the way from Islamabad to Karachi to have an aching tooth taken out.

The Karachi dentist said, "Surely you have dentists in Islamabad! You did not have to come all this way to have your teeth attended to."

"We have no choice. In Islamabad we are not allowed to open our mouths," replied the man with the aching tooth!