Can all dentists know about tmj disorder?

Know about it?: Yes. Treat it? Most do. Really have the experience, training and understanding, especially for the more difficult cases? No.

Yes: Just like all mechanics know about cars, but would take your ford to a chevy dealer for service? Some dentist have acquired additional training and experience in matters related to TMJ issues. Seek out a dentist that is qualified and enjoys treating TMJ issues. You will be spending significant time together getting comfortable.

They should: Most dentists should be well aware of tmj/tmd disorders, but many do not want to treat it. Check with your dentist and consider a specialist.

Maybe: All dentists have learned about the TMJ while in school. There are some that enjoy treating tmd, and have focused a significant part of their clinical practice in the area. There are also those who have continually educated themselves in the field, and some have even dedicated their entire practice to TMJ disorders. For clarification, it is not technically a recognized specialty...

Yes: Yes, properly trained dentists are the experts of the TMJ. Make sure you get an expert opinion from an oral surgeon.