TMJ stands for TemporoMandibularJoint. The joint occurs between the mandible and the temporal bone that is between the lower jaw and the bone at the temple near the eyes. The joint itself can show pain/dysfunction and internal displacement of the disc.
It is also affected by trauma and by systemic diseases such as rheumatoid arthritis. Most clinical problems related to the TMJ are caused by muscular parafunction (e.g. bruxism) or internal disc derangements.
Problems are better known as TMJD (short for temporomandibular joint disorders) or TMD . This term includes problems with the jaw muscles, bones and related nerves.
Pain/dysfunction The most common TMJ disorder is pain or dysfunction.
Symptoms are a combination of:
- limitation/deviation of jaw opening
- joint sounds
- pain on palpation of the TMJ
- pain on palpation of the associated muscles.
Joint sounds alone, or with headache, are not diagnostic of TMJ pain/dysfunction.
Radiology -There is no abnormality visible.
- Reassurance and explanation to patients
- Jaw rest and soft die
- Analgesics/anti-inflammatory drugs
- Occlusal splints to interfere with parafunction may offer some help
- Muscle relaxants.
Disc displacement with reduction
Reduction means that a displaced disc ‘reduces’ into a normal position on opening but reverts to an abnormal position on closing (reciprocal click)
• Clicking on opening
• Clicking on closing
• Transient jaw deviation during opening/closing.
• Consider no treatment other than reassurance and explanation
• Occlusal splints to interfere with parafunction may offer some help
It should be emphasised that treatment should only be considered where the abnormality is affecting the patient’s quality of life; a clicking joint may be considered as normal.
Disc displacement without reduction
If there is no reduction, a displaced disc remains in a displaced position regardless of the stage of opening. This interferes with movement and may cause pain .
• Reduction in opening
• In unilateral cases, lasting deviation on opening
• No click
• Pain may be present in front of the ear.
• Explanation of the condition and reassurance
• Muscle relaxants and physiotherapy
• Manipulation under anaesthetic
• TMJ surgery.
Osteoarthrosis is a non-inflammatory disorder of joints in which there is joint deterioration with bony proliferation. The deterioration leads to loss of articular cartilage and bone erosions. The proliferation manifests as new bone formation at the joint periphery and subchondrally.
It has an unknown aetiology, but previous trauma, parafunction and internal derangements are all suggested as aetiological factors.
• Pain localised to the TMJ region
• Limitation of opening, worse with prolonged function
• Tender on palpation of TMJ.
Plain films show erosions of the articular surfaces of the condyle and, less commonly seen, of the mandibular fossa. Sclerosis of the bone and marginal bony proliferation are seen (Fig. 187) and
narrowing of the radiographic joint space. Bony proliferations
may break away and be seen as loose bodies in the joint space.
• Explanation and reassurance
• Anti-inflammatory drugs
• Restore deficiencies in the posterior occlusion to reduce loading on TMJs
• Intra-articular steroid injections (advanced disease)
• Surgery (advanced disease; final option) to smooth irregular condylar head where there are osteophytes or irregularities.
Rheumatoid arthritis is a disorder associated with synovial membrane inflammation in several joints. The TMJs are involved in approximately half of affected individuals.
• Pain over TMJs
• Tenderness over TMJs
• Swelling over TMJs
• Stiffness and limitation of opening
• Developing anterior open bite and retrusion of chin in advanced disease
• Joints of hands, wrists, knees and feet commonly involved.
Radiology demonstrates reduction in bone density in
the TMJ. There is marked erosion of the condylar head
and articular fossa and narrowing of the joint space.
In long-standing disease, there is:
• destruction of entire condyle
• anterior open bite
• secondary osteoarthrosis
• Analgesics/anti-inflammatory drugs
In dislocation of the TMJ, the condyle is abnormally positioned outside the mandibular fossa but within the joint capsule. Dislocation may occur during trauma or be caused by failure of muscular coordination.
• Inability to close the jaw
• Muscle spasm
Radiography confirms a clinical diagnosis. The condyle may translate beyond the articular eminence normally, without a dislocation, so clinical information is essential. The condyle will be anterior and superior to the ‘summit’ of the articular eminence.
Manual manipulation to reduce the dislocation.
Intravenous sedation with midazolam provides muscle relaxation and greatly facilitates this manoeuvre. The patient should avoid wide mouth opening for some days and use the hand to prevent this when yawning.
Fusion across a TMJ may occur as a result of trauma, mastoid infection or juvenile chronic arthritis. Surgical treatment is by joint replacement with a prosthetic joint unless the patient’s facial development is not yet complete,when a costochondral (rib) graft is used in an attempt to provide a bony replacement that may grow.
For relief of acute symptoms:
- Rest your jaw. This can be difficult, but avoid yawning and other extreme jaw movements and stick to a soft diet. Avoid hard, chewy or crunchy foods. Don’t bite into large foods; cut food into small pieces and chew slowly and gently.
- Apply heat packs or cold compresses (one at a time!) to the side of the face where the pain lies. This is one of the better remedies for many people.
- Doing massages and gentle jaw exercises at home can help.
- Painkillers, anti-inflammatory drugs and muscle relaxants, as prescribed by your dentist/doctor.
- Wear your dental mouth guard, if you have one (and if it helps with relief of acute symptoms).
In the case of severe symptoms, medication may be injected in to the joint for temporary relief from jaw pain. This may be a steroid, local anesthetic or Botox.
Long term management to help the symptoms will depend on the causes as discussed above. Possible strategies include:
1. Mouth guard
Your dentist may make a plastic night guard (splint) that will protect your teeth and reduce the strain on your jaw. This is most commonly used at night to relieve the effects of grinding teeth in sleep although can also be worn during the day when necessary.
If your joint is structurally normal, but your dentist identifies problems with your bite, s/he may suggest various treatments to help with TMJ pain relief:
- If your bite is out of line and a contributing factor the problem, your dentist may recommend orthodontic work as a treatment.
- Bite (occlusal) adjustment – reshaping some of the teeth so that they meet properly and the jaw moves correctly as a result. This is a common option in the treatment of TMD.
- Replacement of missing teeth, as a loss of teeth can affect the way you bite and hence may put strain on the jaw joints.
3. Surgical treatment
In a very few cases where other treatment options have failed and/or a structural problem with the TMJ is diagnosed, surgery may be necessary. This will be carried out by a specialist surgeon, based on accurate findings from X-rays and possibly other scans.
‘Key-hole’ surgery may be possible, involving the use of a small camera beside the joint, accessed from small incisions in the area. More invasive ‘open’ surgery may be necessary in rare cases.
4. Stress reduction
Increased level of stress is often associated with the symptoms of TMJ syndrome. If stress is a factor, is should be dealt with. Your dentist or doctor may recommend professional counselling or psychotherapy. Cognitive behavorial therapy has proven benefits. Relaxation strategies, such as meditation or hypnosis may help in some cases.
TMJ disorders may resolve quickly. Especially if the appropriate preventative and treatment measures from those outlined above are undertaken. Some problems may last longer, especially those that are a result of long-term bruxism or physical disease such as arthritis.
Always consult your dentist with any concerns and s/he will work with you to provide TMJ relief and help reduce the effect jaw pain can have on your well-being.