Thanks for using health Care magic. Read your query. Chronic or acute sinusitis can also present sometimes with pain in the teeth and jaws Is there any recent history of respiratory tract infection or history of allergies? If I were his treating dentist, having found nothing abnormal in the teeth ,would recommended a evaluation from a ENT surgeon to rule the cause if related to the sinus. Continue with the medication as prescribed and visit a ENT surgeon. Keep him hydrated and avoid caffeine drinks if he takes in excess. Hope this was useful. Thanks and regards.