Crunching noise while eating wet food after surgery

Hi there fellow cat lovers!

My 6 month old female got spayed a couple days ago, and ever since the procedure, she has been making an odd crunching/grinding noise when she eats canned food. It sounds like she is chewing a piece of gravel . I have never heard her make this sound before she went under the knife. She is eating a little bit less than normal, but still pretty well, and doesn't seem to be in pain while chewing. I called her vet, but he is out of the office for the day. Does anyone know what might be causing this and what to do?

This is kind of weird, I agree.  I'd call the vet and ask him.

Can you look in her mouth?  (That is, will she let you....?)

My first thought, as irrational, 'out there', as it seems is:  were any surgical instruments in connection with the procedure put in her mouth, however briefly.  Maybe something nicked a tooth.  (I am not a vet, I don't play one on tv, I don't know how the anesthesia is administered to house pets.  It's probably a little different for feral cats.)