My hubby had a tooth extracted and he has had headaches since then. He managed to see a GP and had blood tests and a CT scan and has been to the eye clinic. I keep telling him he needs to ring the dentist as he thinks his nerve might have been damaged as the pain was really bad when he was injected with the local anaesthetic.
I have no idea whether this would apply to your poor hubby but I have heard of something called Dry Socket that affects the area a tooth has been removed from. It's supposed to cause a lot of pain so I agree that you should send your hubby back to the dentist.
I fear dental pain after several nasty childhood experiences and an abscess (probably the worst pain I have ever endured) so I get extremely anxious around Christmas and Easter as I know if I get another I won't get treatment.
I have a few things in my cupboard that I keep for dental emergencies. Nurofen is probably the most effective pain killer I've found for dental pain (but didn't touch abscess pain), clove oil and an emergency filling kit. All through spring and summer I had a gum infection caused by bits of my home-ground flax seed getting caught up under my gum line (I've since stopped grinding it!). I was prescribed Corsodyl by the dentist over the phone who wouldn't see me in person. It worked for a while but I bought a Water Pik that finally cured it.
Corsodyl stained my teeth badly but I'd definitely recommend your hubby try it to see if it will help if there's any infection there. However, I've since discovered Listerine's Advanced Gum (white-ish bottle) and this has been as effective as Corsodyl without the staining.
I hope he gets it sorted soon - definitely before Christmas as if it is tooth-related and he ends up with an abscess he'll have real difficulty getting treated (or at least I would as I live rurally).