Had a tonsillectomy 4 days ago. my teeth hurt . is it related or do i have cavities?

Teeth hurt: Anything is possible, but the stress of going through a surgery could cause you to clench and grind your teeth which could cause them to hurt, definitely go have them checked by your dentist to make sure there are no other issues causing the pain.

Maybe Yes or No: Maybe you have cavities. Or Maybe you have some muscle spasms in the area of the TMJ. Try placing warm moist heat compresses on your face in front of the ears. When warm, slowing exercise your jaw by opening your mouth fully. Repeat multiple times a day.

No: It is most likely referred pain. Sometimes after tonsillectomy surgery, people may complain of an earache and have referred pain to the jaw and neck because stimulation of the same nerve that goes to throat also travels to the ear. However, that does not rule out that coincidentally you also have a toothache.