Can I take benedryl for itching due to dental pain and facial edema?

Allergy/infection. Itch usually means allergic reaction. Pain and swelling usually means an infection that is getting out of control. Benedryl may reduce the itching , but will not eliminate the allergy. Nor will it treat infection. Before this gets out of hand please call our dentist. Treat the cause of the pain/swelling/itching...Don't just mask the symptoms.
I don't see why not. Benedryl shouldn't make the situation any worse. Just make sure you get treated for the infection.