My jaw has locked up to where i cannot open my mouth all the way. i can open and close it, just not open all the way. it is also painful. is this tmj?

Possibly: Tmj is the name of the joint, but it does sound like you have TMJ disorder. A dentist should be able to help. Call ahead to see if he or she treats TMJ pain before scheduling.

TMJ : Yes. This is called closed lock, where your TMJ disc is displaced in front of your joint. Arthrocentesis might be helpful.

Yes: What has most likely happened is that the disc that rides on the top of your lower jaw in the joint space has become displaced anteriorly and is blocking the normal forward movement of your jaw joint. This disc needs to be recaptured so that it rides along on top of the condyle in a normal fashion. A splint may be able to recapture your disc so that your jaw doesn't lock. See your dentist.

Yes: It is called tmd temporomandibular joint disorder. You jprobably have a displaced disc that is making it so the muscles, bone, ligaments and cartilage to not work together correctly.

Yes: Yes, likely a "closed lock". Anterior dispaced disc without reduction. See a TMJ expert to help evaluate and treat your problem. A TMJ expert can be general dentist, an oral surgeon, prosthodontist, orofacial pain specialist. Ask your physician, dentist or dental society for a recommendation.