*Note: I’m not a doctor. See below.
I have TMJD, and there’s varying degrees of it.
For me, it was nausea-inducing, knife-stuck-in-the-side-of-my-head pain that eventually caused me to not be able to eat solid foods or be able to open my mouth very wide. But I never had a locked jaw or noticed any major “popping.”
That is one “version”.
Others have the problem where the little bit of cartilidge between their temporal and mandibular bones (the T and M) slips out, causing the law to be locked open or closed. Some folks can wiggle around and get the disc back in place and go about their business with no pain. Others need medical attention to keep it from happening.
Another “version” is where alignment problems and/or muscle problems cause that disc to degenerate to the point where the TM joint is bone-on-bone. This usually results in painful surgery.
Lots of folks get what you describe. Like you said, it didn’t hurt for a long time, but the muscle might start to hurt or the disc might wear away and become painful.
TMJD or TMJ pain can be caused by genitically weak or wonky jaw muscles or joints, degenerative diseases, tooth misalignment (due to teeth just growing in wrong OR teeth being worn away by grinding), grinding (causing stress on the joint and/or muscle) or alot of times accidents - such as car accidents - that affect the muscles of the head, neck and shoulders.
The pain can feel like a toothache, an earache, a headache, a neckache or a migrane. Or just soreness in the jaw. It can be on one side or both.
For alot of people, a simple splint like Askance describes can do wonders. For me it was a total bite re-alignment through orthodontics (splints, palate stretchers, braces, retainers, more splints) which took about 3 years. The problem came back, on the other side, a few years later but I was able to “catch” it in time so that the re-alignment process only took about 2 years and was much less painful.
As you can see by what I’ve described, TMJD is a really widely-varied diagnosis and can mean many different things. Lots of people will tell you horror stories about their treatments. The surgery stories are the most horifying. But what it comes down to is very patient-specific diagnosis and treatments.
I’ve also been warned that there are few, if any, doctors that specialize solely in TMJD treatment. A doctor that specializes in “craniofacial dentistry” is a good place to start. I believe my doctor is a cosmetic dentist (he does alot of work in South America with kids who need dental reconstruction). From what I’ve read, TMJD is not something that’s covered in much detail in dental school and is more of a topic that doctors have to take upon themselves to research.
One other big thing about TMJD is that it is usually not covered under medical insurance. When I was being treated in 1998, I had one of the nation’s top medical insurance plans - Ford Motor Company’s plan. Denied my claim even though I was in dire pain and could barely open my mouth. I believe treatment is considered “cosmetic” to alot of plans. Sha! Most women I spoke to (about 70-75% of all TMJD sufferers are women) said their plans would not cover anything, not even surgery.
IANAD but from the looks of things you have a really treatable TMJD condition and shouldn’t worry too much about it getting worse as long as you do get some kind of treatment, keep up with it (wear your splint) and make sure you feel comfortable with the doctor that treats you and take note of wether or not the treatment works for you.
Two things your doctor should do every time you visit are use a triangular ruler/protractor thingy (see? IANAD!) to measure how wide you can open your mouth. If the width gets smaller, that’s bad. Also the doctor should stick his/her pinky in your ear and have you open wide. If this causes alot of pain, or if you can’t do it, or if the doctor feels something amiss with the jaw when you do this, it can indicate more problems.
*ok so this is not medical advice. All info that I am presenting is gathered from my own research online and in the library, as well as participation in TMJD patient support forums. I wrote an in-depth article on this subject in 2001 and interviewed several patients across the US as well as several doctors. All that, and I’ve had TMJD since 1998.
For more info Google “TMJ” and “bruxism” (grinding of the teeth)