TMJ Issues -- Need Fuller Understanding

[NCSue]

I have a mare who has a very spastic tongue -- sticks it in and out, wags it around, jerky motion, not rhythmic -- when ridden. Many issues have been resolved or are being worked on. The vet who was out is still doing her osteopath internship and has not yet studied the neck and head in great detail so this was initial findings. The osteopath will be in my area in October and I have an appointment scheduled. What the vet found was that the mare's left TMJ seemed to be functioning normally. She said something like when you press on the TMJ joint with your left hand you place your right thumb in horse's mouth. The pressing and horse's swallowing should be in the same rhythm. This was true on the left side. On the right side (the side mare seems to have difficulties with) this was not true. She was not rhythmic. For my own education I would appreciate any enlightenment. Does this mean an alignment issue? Or does this sound more like a neuro issue?

[fourmares]

You might also have her hyoid looked at. It is the bone in the tongue. (Yes, there is a tongue bone). It can fracture, or the joint where is attaches to the base of the skull can become inflamed or get arthritic. The most likely cause is someone mishandling the tongue while examining the teeth.

[Pancakes]

I would have radiographs or an ultrasound done to evaluate the joint -- you can see changes if indeed there is arthritis there. You could also do a head-only bone scan to see if one TMJ has more activity than another.