The Reid wrote:

Following up to Martin W. Smith

If you havnt eaten, the growling is normal

Because you say so?

If you like!
Is it not commonly reported? When I last went to the dentist sans
breakfast I apologised for the rumbling, although dentists are
not doctors, they tend to medically aware, he did not seem to
think I had any problem, just in need of a croissant which I
couldn't eat until my gums had been treated.

next time you go to your dentist, as he/she enters the room
act like you are chewing and then hold up an oreo cookie and
mumble, "you want one?" the look of disbelief on the dentist's
face is going to be priceless.