Hello, My Husband Had Dental Work Done About 2weeks Now

Hello, my husband had dental work done about 2weeks now they had to use a large amount of lidocaine to numb his mouth and then put crowns on. The temps didn't bother but now he complains about jaw pain not the teeth but jaw that starts in the back on the left and radiates down the mandible. So bad I had to call and have the dentist call in a prescription that is stronger than the Tylenol and ibuprofen. He has already returned to the dentist and they took X-rays but they said they did see anything. He travels out of town 100%of the time so it is not that easy for him to just go back. Is there any suggestions, or advice that he can do until he can get back?