Please tell me what can be causing my dad's toothache and ear ache?

Cavity ?: Just a guess. It needs to be seen by a local dentist, so call and make an appointment.

Difficult to: Diagnose without an exam and x-ray. Best to be evaluated by a dentist asap. Hope this helps.

Can't: Must be examined ; probably x-rayed to determine cause, and thereby the appropriate treatment. Toothache usually means infected tooth, but can have other causes. Earache may be referred pain, joint problem, ear infection, etc. Start w trip to your dentist, but may also have to see physician.