What is the temporomandibular (TMJ) joint?
The TMJ is the jaw joint where the lower jaw (mandible) attaches to the side of the skull at the temporal plate. Join the two together and you get the temporomandibular joint or TMJ.
It is like a finger joint – two bony bits with cartilage on the surfaces that articulate against each other. Unlike the finger joint, the TMJ has a cartilage disc in between each surface and there is a two stage movement – rotation and then a glide or slide – as opposed to the normal one stage movement of most joints.
What is temporomandibular syndrome and TMJ disorder?
Any problem with the TMJ could be considered a TMJ disorder. These TMJ disorders range from minor discomfort to significant pain in or around the jaw joint and the joint may click with, or without pain.
The clicking of the jaw is a result of muscle tightness that is forcing the lower jaw hard up into the temporal bone of the skull. This creates excessive compression in the joint. Within the TMJ, there is a small cartilage disc. If there is too much compression, it can become dislodged. This is what happens if your jaw clicks when you open your mouth. The increased compression does not allow all the components of the TMJ to go through their normal ranges of motion, and the little slide disc gets jammed, resulting in the clicking noise.
My jaw used to click, but after formulating exercises to reduce the tension in the muscles, it rarely clicks now. Jaw clicking can be resolved with the right stretching and massage exercises. I have successfully treated many people with jaw joint disorder at my clinic. From actors who were unable to articulate words clearly due to jaw fatigue, teenagers with teeth grinding problems, to parents with jaw movement or clicking issues.
Jaw Joint Dysfunction
Joint dysfunction can range from mild inflammation to complete degeneration where the cartilage has completely gone and there is bone on bone contact which ultimately, will need surgical intervention. One of the more common presentations I see at the clinic, is where someone’s jaw has ‘gone out’. They are unable to open their mouth more than a few millimetres. This is common after long appointments at the dentist with extended mouth opening, after a big yawn or after some hard chewing on tough meat. In these situations, the jaw never actually goes out or dislocates. It’s more that the muscles were already a bit tight and had to perform an activity they weren’t used to. This strained and inflamed the muscles. However, like any muscle strain in the body, you can slowly and gently stretch it back to normal function. This generally requires careful osteopathic treatment.
Chronic Jaw Problems
The most common cause of chronic jaw problems is hyper- tonicity of the muscles of mastication. Simply put, the muscles we chew with are tight and have been tight for a long time. The result is clenching or gritting the teeth of the bottom jaw hard against the top teeth. It is usually an unconscious action during the day, and also when asleep.
Clenching your teeth in your sleep is often accompanied by grinding. This is known as Bruxism. If this condition persists for long periods of time, it will eventually wear the teeth down. I have seen teeth that have been worn down to flat plates and are getting close to the underlying nerves. The chewing muscles have a higher number of neurological connections with the emotional centres of the brain. Therefore any actual, or perceived stress, will trigger a higher response in the muscles of the jaw than in most of the other muscles in the body.
Jaw fatigue (neuromuscular fatigue) can present itself in many ways. Jaw muscles that ache and become exhausted to the point you can’t be bothered chewing are just one of the causes of pain associated with temporomandibular disorders. Sometimes the TMJ can become inflamed making chewing difficult and painful. Temporal Arteritis can be another reason for difficulty with chewing.
Temporal arteritis is when the jaw muscle lacks sufficient blood flow thereby causing pain when that muscle is used. Tender scalps, loss of vision in either eye, plus pain in either your shoulder joint or hip joint are other symptoms of temporal arteritis.
Weakness and fatigue in the neck and jaw can occur in the early stages of Myasthenia gravis (MG). Bulbar nerve weakness (nerves that originate from the part of the brainstem that resembles a bulb) can make your speech sound slurred and nasal. You can also experience frequent choking spells, and eating becomes unpleasant and tiresome. If you display any of these symptoms, seek the advice of your osteopath or doctor.
If you want to see temporomandibular disorders, joint and muscle disorders and how the jaw functions explained visually with 3D animation, watch this Jaw Introduction Video. Remember; if pain persists seek medical assistance.