My husband had a filling done about 3 weeks ago and since has been suffering jaw pain. is there any explanation for this?

Jaw joint?: Sometimes the jaw joint can become injured during dental procedures. By having the mouth open very widely the muscles around the jaw can be stretched and tear leading to pain and discomfort. He should use anti-inflammatory medicines, ice 20 minutes 3 to 4 times a day on the area that hurts and a strictly soft diet. He also needs to contact his dentist for an exam.

Yes: You should have returned to your dentist after the first day of discomfort. The filling is probably on the nerve which can be very painful. If that is the case you will need root canal therapy. The pain could also be the result of a fracture in which case you will need the tooth removed.

Injection: His discomfort may be form the injection. Sometimes there is soreness at the injection site or area. It could be something else swell.

Several options: Post op jaw pain has many possible causes. It could be nerve (pulp) inflammation and pain, TMJ pain, the result of opening excessively, especially if there is a pre treatment bite problem. Incorrect bite after treatment, trauma from the injection, or infection.