What are the recommended treatments if my lower jaw shifts to the left when I open my mouth?
When I open my mouth, I can see my lower jaw shifting to the left. My jaw shifted many years ago. At first I could hear a lot of cracking sounds. However, over the years, I can't hear much just a little cracking sound when I open my jaw. What treatment would be recommended?
Dear alethea96 g3,
It sounds like you have 2 issues that concern you.
1) Your lower jaw shifting to the left on opening
This is usually caused by some jaw joint (temporomandibular joint, or TMJ) degeneration on the left. TMJ disease ranges from elongation and distortion of the cushioning disc found between the bony surfaces of the joint to osteoarthritis (degenerative changes of the bony joint surfaces).
These changes may cause restriction in the full range of joint movement on the affected (left) side and may even be painful.
The right and left TMJ can move as a hinge (like how a door opens), as a pivot (rotation around a central point) and also slide forwards and backwards (translation). If one side of the joint is restricted, then the pivot and translation movements may be lost. The unaffected/less affected side (the right side, in your case) will compensate for this and the entire lower jaw tends to rotate and shift towards the affected (left) side.
2) The cracking sound that occurs when you open your mouth
As a result of the degenerative changes in the TMJs, 2 sources of joint noise may be present.
The first is the grinding of the unprotected bony joint (articular) surfaces against each other during movement. Osteoarthritic changes cause the protective cartilage that covers the articular surfaces to wear away and cause tiny bony spicules and irregularities to build up on the articular surfaces. This prevents smooth gliding joint motion from occuring. The sound linked with this is usually described as crackling.
Most adults show signs of osteoarthritis of the TMJs even at a young age because this is the most heavily used joint in the body. Fortunately, most of us do not experience any pain or limitation in our joint function because the TMJ and jaw muscular system is very adaptable, especially if the changes are gradual.
The second source of joint noise is caused by the cushioning disc hopping on and off the condyle (the mobile bony component of the TMJ, which is part of the lower jawbone) as you open your mouth wide. The disc tends to be bunched up in front of the condyle when the jaw is at rest and as the condyle slides forward, this causes compression of the disc and stretching of the elastic part of the disc that is attached to the base of the skull. When sufficient tension is reached in the elastic area, the recoil effect pulls the disc backwards, forcing it between the bony joint surfaces. This creates a popping or clicking sound.
Depending on when during the opening/closing movement the disc is squeezed between the bony surfaces, you may notice this clicking sound only when you open, only when you close or during both opening and closing your mouth.
Determining the exact source of the joint noise will require investigations such as MRI or even CT scans of the TMJ. Arthroscopy (viewing the internal workings of the joint through a pinhole camera) may also be used.
However, long term research has shown that MOST patients with degeneration of the TMJ tend to:
A) Not experience any worsening of their symptoms
B) Improve spontaneously over time, which sounds like your situation.
Both these outcomes are observed when NO treatment is provided. We still do not understand why certain patients get worse faster than others. We still do not understand why TMJ disorders (TMJD) seem to affect more women than men, and the age groups most affected are young (18-25 years old) or older (aged 50 and older) adults.
I DO NOT think that joint surgery (arthroscopy) is useful for the vast majority of TMJD patients since long term outcomes tend to be the same as if no treatment was provided. Some surgical patients find that their range of motion may even worsen because of the scar tissue caused by the surgery.
The only type of TMJ surgery that may be useful is an eminectomy (reduction of the steepness of the bony joint surface that guides the condyle). This is only done for patients who have repeated episodes of open/closed locking (unable to open or close their mouths) of their TMJs.
Most patients with acute TMJ problems benefit from painkillers, resting the joint (avoiding hard foods that require a lot of chewing, limiting wide mouth opening) and a mouthguard if they do grind their teeth in their sleep (bruxism) since this leads to overuse of the TMJs and accelerates degeneration. The vast majority of patients see improvements with these simple non-surgical methods.
If the joint noise has reduced and is not bothering you significantly any longer, I would just choose to leave things alone!