To be honest, that's why I mentioned 'if you can find one'.
I had to travel an hour each way to see the guy I found and my case worker while I was on leave from work found him for me. She said I was very fortunate that he's practicing in this area, because they're rare (dental pain specialists that is).
He ran a few EMG's on me (dentist) which were quite telling of a lot of pain conditions.
In the end, he diagnosed TMJ and TN/ATN (atypical trigeminal neuralgia), but he also picked up on things like abnormal swallowing which is seeing with... dundundun... MS!