The TMJ or the Temporomandibular joing is located just in front of the ear and is composed of the temporalis bone and the mandible. There is a little disc within the joint and a group of chewing muscles. There is great variability in the shape of the two halves of the joint, which add to the difficulty in treating this area. You can suffer from many symptoms if you have a problem with your TMJ.
The joint is subject to degenerative changes, the lower portion tends to be more vulnerable to these changes than the upper portion but the amount of degeneration is not found to relate to the amount of pain a patient reports. The disc is subject to complicated movement and has several attachment sites within the joint. These multiple attachments result in potential displacement of the disc in all directions.
Head, facial and neck muscles all contribute to TMJ movement. The muscles of chewing are the primary muscles associated with the TMJ and include the lateral pterygoid, geniohyoid, mylohyoid and digastric muscles. Primary closers include the temporalis, masseter and medial pterygoids. These muscles are responsible for the muscle pain often closely associated with TMJ pain and are related to either teeth grinding and/or the formation of painful trigger points in the relevant musculature.
The movements of the TMJ are complex. The joint is known as a hinge and sliding joint but also utilizes spinning and compression movements. The right and left joints act together to move the lower mandible relative to the maxilla, temporal bone and cranium. On mouth opening, a combination of rotation and movement forwards occurs and on mouth closing rotation and movement backwards should occur.
Pain in the TMJ is common, affecting between 5 to 60% of the population. Progression to severe pain and recovery from frequent symptoms are equally rare in the majority of cases.
Examination of the joint
We take a full patient history, to ascertain the exact symptom location, pain intensity ratings, symptom type, symptom behaviour and related areas of involvement in order to arrive at a diagnosis.
You will be asked about the following:
- history of emotional or psychological stress,
- medication usage,
- symptoms of blood supply problems to the brain,
- upper neck instability,
- cardiac dysfunction,
- central nervous system dysfunction,
- cranial nerve dysfunction,
- unexpected weight loss or gain.
We will look for
- general postural problems,
- relative prominence of the facial and neck musculature,
- gross mandibular size and shape,
- regional symmetry,
- mandibular resting position,
- both skin temperature and colour,
- abnormalities of the oral structures, and
- condition of arteries, veins, lymph nodes).
- Range of movement which involves active range-of-motion testing including mouth opening, right and left lateral deviation, and protrusion.
- Passive Accessory Movement Testing, which involves distraction, anterior glide, medial/lateral glide, and caudal/anterior/medial (CAM) glide of each mandibular head and sometimes requires us to put on gloves and put a finger or thumb into your mouth.
- Feel if you have any of the following:
- pain at the TMJ line,
- abnormalities in mandibular head movement,
- hypersensitivity of the tissues behind the disc with an open mouth,
- popping or clicking,
- regional tenderness,
- regional muscle trigger points, and
- changes in mass of the masseter, temporalis, pterygoid muscles and neck muscles.
What can be causing the pain?
Associated with stress, anxiety, clenching or grinding of the teeth
Can involve arthritis, too much movement in the joint, too much compression within the joint or movement irregularities.
Disc Displacement with Reduction:
Associated with joint noises (popping/clicking) and maybe also blocked opening of the mouth.
Associated with possible movement of the disc forwards or backwards which blocks jaw opening.
Neck pain usually in the upper neck are generally present in all TMD cases
May include any of the following:
We will check your posture and make recommendations – for example if you sit hunched over a lap top for hours, your jaw and neck muscles will tighten and cause reduced function in the TMJ.
We usually try to help to improve joint movements by gentle joint mobilisation and reducing muscle spasm. We mobilise in all of the movement directions of the TMJ but avoid this if you are showing signs of too much movement (hypermobility). Considerable evidence exists that supports the use of mobilisation. We will often teach you self-mobilisation to help speed your recovery.
Soft-Tissue Mobilization means working on any tight muscles that we have found around your TMJ
Trigger point dry needling (acupuncture specifically designed for muscle and joint pain) is very helpful when muscle tightness is diagnosed. Verity Moore and Richard Barton both use this treatment.
Research indicates that friction massage be very effective.
Exercise programs specifically designed to address TMJ problems are not thought to be particularly helpful.
Anxiety and stress management.
Nocturnal grinding of the teeth ( bruxism) is generally an unconscious action and can be helped by referring you to a dentist who deals with bruxism and they may recommend a splint made of clear plastic that fits over your lower teeth. Splints are designed to be worn at night to limit nocturnal bruxism and minimize muscle contraction. You can also grind your teeth while you are awake, when bruxism is consciously performed, for example when concentrating on something or when you get angry or stressed. Yoga and relaxation classes are available at the clinic to help with stress.
We will examine your neck and treat that as necessary and also mobilise the disc in the TMJ to alleviate problems with opening or closing your mouth and to reduce pain or clicking when you open or close your mouth.
What if We Can’t Help?
Surgery may be indicated for some patients, mainly when conservative treatments are not successful. It is usually supported by non-invasive treatment before and afterwards. Surgical options include:
Therapeutic arthroscopy – when the joint is washed out.
Removal of loose bone fragments.
Reshaping the condyle.
More complex procedures, including joint replacement.
Botulinum toxin A (BtA) injections:
If we cannot help you, we will refer you on to a TMJ specialist but our treatment is often very effective, no matter how long you have had the problem so it is worth consulting us first before trying the more invasive treatments.