My wife has had some success with this. You can find information and a practicing Dr at nucca **. She goes in every 3-4 weeks or so for treatment. The treatment involves slight movement of the cervical atlas (C1) vertebra only, rather than the entire spine.
The treatment does not relieve her TN/nerve deafferentation pain. The relief comes from the elimination of tension built up in the neck/shoulder area. I think most folks living with chronic pain in the head/facial area naturally develop tension in these areas over time. After each treatment she is able to sleep better, reports being more relaxed, and in general is able to "deal" with her chronic pain better. Our insurance does not cover the $50 visit, but it's well worth the cost for her.
My advise seeking any type of chiropractic care: In my experience, these folks are usually initially pretty confident about being able to "cure" cranial neuropathic pain. I would meet this with more than a little skepticism. I believe they are worth working with for the above reasons, but please don't get your hopes up about a cure or significant relief of this type of pain from a chiropractic standpoint. I would hope to be wrong about that, but after 12 years of dealing with this pain our experience has shown otherwise.