The work in the temporomandibular joint, on the horse, is a similar technique I was taught through an osteopath, on releasing tension within my mastoid, tmj, neck, hyoid, and other painful areas that my right side holds on too.
I find these similar problems and compensations in horses too!
With this tension comes extra sensitivity of the face, ears, and poll and possible nerve pain (something I have experienced in its entirety).
Through massage I am able to pick up on the differences of each side and compensating muscle.
As the body begins unwinding with each session this continues to help prevent the same triggers from coming back so progress can be made. Throughout consistent work this is where we end up with a maintenance schedule to... persist with less pain and prevent.
All the little releases add up to the bigger results throughout the body.
learn more about this technique along with identifying pain and behavior in horse in this free class --> FREE CLASS | EQUINE PAIN AND BEHAVIOR (equi-ix.com)