What Causes Pain In Jaws After Tooth Extraction?

I had a lower molar extracted 4 weeks ago. Prior to the extraction I had gum pain for weeks. My dentist said he didn t see anything when I went for my cleaning. Then within a couple weeks of the cleaning the tooth cracked down into my gum. He pulled the tooth in the office. It was very difficult to get out. At that time he told me that there was infection present but it would come out with the tooth. He didn t put me on antibiotics. I had extreme pain for the first 4 days, and went to the medical center. They put me on antibiotics, and I returned to my dentist the 5th day. He said it was fine - normal to have that pain and that I didn t need the antibiotics but I could keep taking them. I have had considerable pain every day since then which now radiates into my entire jaw- both sides and into my temples. My jaw aches and I m on my second round of antibiotics and have been taking pain meds since the extraction. What could be causing this pain???