Hi Moose,
TMJ is my main tms woe so I empathise completely. Like everyone else here who suffers with it, all treatment roads have led nowhere. Mercifully though I have a fairly evolved dentist and his biggest and best advice is to relax. Any remedy he employs is in the interests of damage limitation. Clenching or grinding is very common, especially in the current financial climate he tells me, and a lot of people find their pain passes when they realise nothing is actually wrong with teeth or jaw. I'm a stubborn case but own the fact that it's because I've allowed stress to run rampant (we do before we know how to be kind to ourselves).
The pain one feels in the jaw, neck, shoulders, scalp or face with tmj comes from bracing. The unconscious does all it can to protect the teeth themselves and this has a knock-on effect.
In my experience and my best advice is soothing is good. Consider the ole soothe-rage ratio. TMJ has it's genesis both literally and metaphorically in pressure. Where in your life are you overwhelmed? Where have you traded pleasure for responsibility? Where and with whom do you need to say no? Assert your boundaries? Beyond anger, look to rage. You'll find it. Red tooth and claw - classic fight behaviours. Your primal self is screaming in it's Unspoken Voice.
Hope some of this helps.
Be kind where you can, let go the small and the silly, and smile. There is no better tonic for tmj than laughter.