OH YES, thank God, but for me it took a lot of time and frustration, sadly. Whereas, there might not be a "cure" for your girlfriend, depending on how long and how much damage there is, she can be helped, I believe. One of the most important things to do is find a good TMJ dentist. This is the frustrating part usually.
I do advocate bite splints but frequently other treatments must be done at the same time (PT, MT, medications, ultrasound, TENS, posture correction, etc.) You could be one of her best "doctors" by learning the basics of trigger point massage and doing this on her every day, tho, this is usually just a band-aid, not a cure. Frequently it takes many band-aids to control TMJ.
I hope and pray that she can find the help she needs. Research and learning all you/she can about TMJ. It will help when trying to find what treatment(s) will work. Trial and error is common with TMJers; sadly. Please, just love her. I know that as the person not experiencing the pain, you can't really know all she is going thru, but I can guarantee you it is a nightmare. Support can be a big band-aid in itself.
God bless you both,
Carol