There is a chance you have atypical trigeminal neuralgia.
You should try to find a neuro who has exp. in this.
An MRI can rule out TN 1, or classic TN. But your symptoms sound more "atypical". The meds most known to help are Gabapentin and a Tricyclic AD, like Elavil or Desipramine. Heat on the area might bring a little temp. Relief. I'm so sorry...sounds hideous and the dental prof. is often clueless or WORSE when it comes to this topic!