Temporomandibular joint (TMJ) disorders

Your temporomandibular joints are your jaw joints. You have two, one on each side of your face, and you can feel them by putting your fingers just in front of your ears and opening your mouth. Temporomandibular disorders, usually shortened to TMDs, are a group of more than 30 conditions that cause pain and difficulty in these joints and in the muscles that move your jaw.

What are the symptoms of a TMJ disorder?

Clicking or popping in your jaw joints without any pain is common, considered normal, and doesn't need treating.

Symptoms that may point to a TMJ disorder are:

• pain in your chewing muscles or your jaw joint, which is the most common symptom of all
• pain that spreads into your face or neck
• stiffness in the jaw
• limited movement, or the jaw locking
• clicking, popping or grating when you open or close your mouth, where it also hurts
• ringing in the ears, hearing loss or dizziness
• a change in the way your upper and lower teeth meet.

The pain is usually a dull ache in or around the ear, which can travel forwards along the cheekbone or downwards into the neck. Chewing tends to make it worse, and symptoms often flare when you're stressed.

Many TMJ disorders last only a short while and clear up by themselves. In some people they become long-lasting.

What causes TMJ disorders and who is at risk?

For most people the exact cause isn't clear, and symptoms often begin with no obvious reason behind them. An injury to the jaw joint can cause some TMJ disorders, but that accounts for only a minority.

Research points to a combination of things working together: your genes, psychological and life stressors, and how your body processes pain. This is why two people with similar jaws can have very different experiences.

TMJ disorders are more than twice as common in women as in men, particularly in women aged between 35 and 44. This is due to hormonal fluctuations – relaxin and oestrogen receptors affect structural stability and flexibility, and the levels of each are affected by fluctuations from menstruation , menopause and hormonal contraceptives etc.

One belief is worth putting straight. Research does not support the idea that a bad bite, or having had orthodontic treatment such as braces, causes TMJ disorders.

Are there different types of TMJ disorder?

There are three broad groups, and you can have more than one at the same time:

• Disorders of the joints themselves, including problems with the disc of cartilage inside the joint.
• Disorders of the muscles you use for chewing.
• Headaches caused by a TMJ disorder.

Knowing which group your problem falls into matters, because it shapes which treatments are worth trying.

How is a TMJ disorder diagnosed?

There's no single accepted test for TMJ disorders. Diagnosis can be difficult, because these conditions have different causes and their symptoms overlap with other problems.

Your doctor or dentist will take a detailed history. Expect questions about where and when the pain happens, what makes it better or worse, and whether it spreads into your jaw, face or elsewhere. They may also ask about other pain conditions such as headaches or back pain.

They'll then examine your head, neck, face and jaw, checking for tenderness, for clicking or popping, and for difficulty moving the joint.

Imaging is sometimes arranged, which may be an X-ray, an MRI scan or a CT scan.

Pain in your mouth, jaw or face doesn't always come from the jaw joint. Your doctor or dentist may need to rule out other conditions before settling on a diagnosis.

How is a TMJ disorder treated?

Three things are worth knowing before any treatment starts.

1. Joint sounds without pain are normal and don't need treating.
2. Symptoms go away without any treatment for many people.
3. The evidence behind many TMJ treatments is limited, so experts recommend starting with conservative options and avoiding anything that permanently changes your jaw joints, teeth or bite.

First steps

Many jaw joint and muscle problems are temporary and don't get worse, so simple measures are often all that's needed. When symptoms first appear, your doctor or dentist may suggest that you:

• eat soft foods that need little chewing for 7 to 14 days, so overworked muscles can rest
• apply heat or cold to your face, alongside exercises to gently stretch and strengthen the jaw muscles
• take over-the-counter painkillers, such as non-steroidal anti-inflammatory drugs
• cut down habits such as clenching your jaw, chewing gum or biting your nails.

Ask your pharmacist if you're unsure which painkiller suits you.

Physiotherapy

Physiotherapy aims to keep, improve or restore movement. Research suggests manual therapy, where a therapist uses their hands to stretch the soft tissues and muscles around the joint, can improve function and relieve pain.

Self-management and psychological approaches

Self-management means the things you do yourself: learning about your particular type of TMJ disorder, noticing and reducing habits such as clenching or gum chewing, practising relaxation, and staying involved in the activities that matter to you.

Cognitive behavioural therapy can help – it’s a pyschological therapy that works on identifying unhelpful thought patterns and building coping skills, to help with any stress that’s causing the TMJ disorder.

Medicines

Over-the-counter anti-inflammatory painkillers are the usual starting point. Prescription options exist, including medicines for anxiety, antidepressants, antiseizure medicines and opioids.

There's limited evidence on which medicines work best for TMJ pain, and some carry a risk of addiction or other serious side effects. If you're prescribed anything, ask your doctor or dentist how to take it and for how long.

Mouthguards and splints

These are devices worn over the teeth. They protect your teeth and may help you break the habit of clenching. They go by several names, including nightguards, splints and bruxism splints. They should only be used after a dental assessment.

There isn't a lot of evidence that they reduce TMJ pain. If one is suggested to you, check that it isn't designed to permanently change your bite, and stop using it and go back to your dentist or doctor if it causes pain.

Procedures and surgery

These treatments are more involved. They mean going into the jaw joint or the chewing muscles with a needle or an instrument, or changing your bite and teeth. Some of them don't work, and some can make the problem worse.

Before agreeing to any of them, ask about simpler treatments and try those first. Ask for a clear explanation of how the procedure would help your specific problem and what the risks are, and get a second opinion from a qualified specialist.

The options, and what's known about each:

• Occlusal treatments: These change your teeth and bite, through crowns, grinding down teeth or orthodontics. There isn’t enough evidence that these work for TMJ disorders, and in some cases they make things worse.
• Prolotherapy: This involves injecting a solution into the joint area to trigger repair. It shows some promise where the joint dislocates or moves beyond its normal range, but only a few small studies have been done.
• Arthrocentesis: This uses a needle to flush liquid through the joint, breaking down scar-like tissue and washing out substances that cause inflammation. It can relieve pain and improve mouth opening where the disc is out of place, though results have been inconsistent.
• Arthroscopy: This involves putting an instrument with a tiny camera into the joint, which helps with diagnosis and allows scar tissue to be removed or the disc repositioned. It works moderately well for pain and function.
• Open surgery: This reaches the joint through a cut next to the ear. It makes permanent changes, and there is no long-term research on how safe it is or how well it relieves symptoms.
• Joint implants: These replace part or all of the jaw joint. Some studies suggest they can improve function and quality of life in carefully selected cases.

Open surgery should only be considered where the joint is damaged beyond what other procedures can fix, or where pain or difficulty opening the mouth remain severe despite trying everything else.

Implants are considered in a narrow set of circumstances – injury to the joint, a condition present from birth that needs repair, a joint that has frozen after injury or infection, severe damage, or ongoing pain where all simpler treatments have failed. Some implants used in the past caused serious complications and were withdrawn, and researchers are still studying the long-term safety of current ones.

When should I see a doctor?

See a dentist or doctor if you think you have a TMJ disorder, particularly if the pain is affecting your eating or your sleep.

It’s worth raising if:

• your symptoms aren't settling after a few months
• self-care measures aren't controlling the pain
• your jaw is locking, or you're finding it increasingly hard to open your mouth
• you've noticed a change in the way your teeth meet.

Start with simple treatments, and remember that symptoms often go away on their own. Before considering anything irreversible, such as surgery, implants, or treatment that permanently changes your teeth, bite or joints, talk through the benefits, risks and alternatives. Getting a second opinion from an orofacial pain specialist is worth doing if you can.

If your symptoms persist after 3 months despite conservative measures, this is the point at which your GP should refer you to a maxillofacial specialist.