Temporomandibular Joint Dysfunction
Updated: Feb 27, 2019
The temporomandibular joint, commonly abbreviated to the TMJ is the scientific name for the Joint between your Jaw and the skull. It is one of the most utilised joints in the body due to its role in opening and closing the mouth, talking, breathing, clenching and particularly chewing.
In addition to the extensive use this joint receives, it is also prone to damage due to its unique design. The shape of the bones that make up the TMJ are not congruent with each other and so to compensate for the incongruity there is a small disc or meniscus between the bones.
This disc divides the joint into an upper and a lower portion, with the lower portion being responsible for rotation of the TMJ and the upper portion accounting for translation. The kidney shape and position of this disc predisposes it to getting caught in the joint which can account for TMJ pain and clicking.
Symptoms of TMJ dysfunction can include:
· Pain in front of the ear
· Clicking, grinding or popping
· Movement restriction when opening or trying to slide the chin from side to side
· Catching or sharp pain with movement (i.e. opening)
· Pain over the side of the skull
· Jaw locking
· Jaw subluxation or dislocation
The TMJ also has several ligaments to stabilise the joint and several muscles to move the joint.
Interplay of these muscles and ligaments allows unimpeded movement through the TMJ. If the ligaments are lax (trauma) or the muscles tight (overuse) this disrupts movement patterns and puts excessive pressure on the joint leading to wear and tear of the articular disc which leads to popping, clicking and pain.
The main muscles involved in movement of the TMJ are the masseter and buccinator (cheek muscles), the temporalis muscle (side of the skull) and the pterygoid muscles (accessed through the inside of the mouth).
Common causes of TMJ dysfunction are:
1. An acute injury, such as a blow or fall, in which the jaw is subluxed, dislocated or fractured
2. Excessive teeth grinding which causes wearing on the articular disc
3. Excessive muscle tension from grinding or chewing
4. Extreme ranges of movement such as yawning
5. Prolonged dental procedures
6. Poor posture and upper cervical stiffness
A TMJ dysfunction can be diagnosed by your therapist or more commonly by your dentist who will then refer you to a physiotherapist to perform a full assessment. In this appointment your therapist will look at your posture, jaw range of movement, muscle tension and joint restriction. They will also perform a thorough assessment of your cervical spine, as often TMJ and cervical stiffness will occur at the same time.
At the conclusion of this assessment your therapist will be able to tell you if the cause of the problem is a closing problem (grinding) or an opening problem (restriction in the muscles and joint on the affected side).
If the problem is of a closing nature then often you may be referred back to your dentist to have a splint made prior to undergoing therapy. If the diagnosis is an opening problem, then treatment can begin immediately. Common methods we use in the clinic include ultrasound, dry needling, Soft tissue release, joint mobilisation to the TMJ and upper cervical spine (neck) as well as a targeted program of postural correction, muscle stretching and joint mobility exercises.
Due to the nature of the cause of opening disorders, manual therapy is normally very successful in resolving the problem. However, in order to minimise the risk of developing TMJ dysfunctions here’s a couple of quick tips:
1. Posture, Posture, Posture! Sitting with a forward head position is a primary cause of TMJ dysfunctions, so make sure you have a good ergonomic set-up and engage in plenty of chin-tuck exercises.
2. If you notice that you clench or grind your teeth a lot, during the day or at night, visit your dentist to assess whether a splint may be beneficial
3. Try to distribute your chewing evenly over both sides, chew smaller mouthfuls and avoid hard or chewy foods.
4. Avoid chewing Gum
5. Avoid extreme jaw movements such as yawning and yelling, and when you do yawn support your chin with your hand.
6. Massage tight or sore muscles through the checks, jaw and temple muscles
7. Avoid resting your chin on your hand.
So that’s a brief overview of how TMJ dysfunctions can occur, If you have questions or comments feel free to e-mail us at firstname.lastname@example.org and we will be happy to answer them for you.
If you think you may already be suffering from a TMJ dysfunction, then addressing it sooner rather than later is crucial. So, if you want relief now, call us on (08) 9486 8653 and we will arrange an appointment for you.