depression and TMJ
I realize this reply is a year or so late, but when I saw it, I just wanted to add my experience. About five years ago, I was severely depressed and was suffering from terrible TMJD. I experienced periodic numbness in my arms, hands, and upper back, as well as headaches and neck pain. The depression preexisted the TMJD, but everything got worse with the pain. I had been to specialists, therapy, slept with an expensive mouthgaurd (which I gnawed in my sleep, cracking it), and still didn't find any relief. I could go on, but I'll just say I was miserable.
Anyway, I saw a friend for an hour of trigger point therapy, and towards the end of the session she somewhat hesitantly asked me if I was up for her to address some trigger points inside my mouth (she warned me it could be quite painful). At that point, it seemed worth a shot.
It was beyond excruciating that first time, but after a few minutes, she was done and everything had changed. Before I was off the table I was marvelling at how much relieving the pain had changed my outlook. Ten minutes later, I began working out plans to go to massage school (which had never been of interest before). I remained free of jaw pain for 9 days, at which point I had a follow up treatment, and then weekly for a couple of months. Five years later, no jaw pain and a career I'm still passionate about. (The few times I have experienced jaw tension from teeth grinding since, I've self treated inside my mouth and eliminated the discomfort.)
In clinic, during school, I had a client with bad TMJD, and he also experienced tremendous relief from trigger point work inside his mouth (of course supervised by my instructor who I had practiced on already). Also, I've used reiki on clients where inside the mouth work wasn't appropriate, or when we just needed a less invasive approach.
That turned out to be a longer post than I had intended, but, if your loved one still has jaw pain, it's definitely worth a shot to go at the trigger points. If your loved one is not still in pain, even better.