I had my wisdom teeth out 3 days ago and my lower jaw is sore with pain...is it okay to apply a heating pad to it to reduce the pain?

Yes: Moist heat is the best.

Yes: I see no reason why not.May have to take pain medicine as prescribed.May be sore for a week or so.If condition worsened, see your dentist asap.

Jaw Pain: After only 3 days it's normal to have some pain at the surgical site. I generally recommend ice for the first 3 days, then moist heat beyond that. If your pain persists or worsens, return to see your oral surgeon for an evaluation to see if there's a problem with healing, and follow their instructions.