My jaw has been stuck for 2 days and i can hardly open two fingers wide. what will the dentist do to treat me?

Physical therapy: Probably give you some anesthetic, massage your jaw, then prescribe a muscle relaxant.

Several easy things.: First he/she may take an x-ray of the jaw (from the outside) to verify that it there not a tooth causing the problem. If it is solely a jaw joint problem, several easy things may be sugested--hot and cold therapy on the jaw joints, muscle relaxants, soft diet, sleep on your back (not on your side) anti-inflammatory meds, and possibly physical therapy. Call your dentist for guidance.

Warm wraps: Depending who you seek if you go to a neuromuscular dentist they will tens you at a low frequency and will be able help you tremendously.

Oral Surgeon ASAP: See an oral surgeon who treats TMJ ASAP. Sounds like you may have a "closed lock" or non-reducing disk displacement. Some TMJ "experts" will treat this with a splint. If you manipulate the locked disk free, you then have a better chance of long term TMJ heatlh by then using traditional modalities of TMJ treatment.