About the TMJ

The Temporomandibular Joints (TMJ) are the most important and most used joints in your body. They are constantly working to allow you to talk, eat, chew, sing, yawn and bite. Dysfunction within your TMJ can be extremely debilitating.

It is estimated that approximately 20-30% of the general population are affected by TMJ pain by some degree. Temporomandibular disorders (TMD) is an umbrella term for pain within the TMJ and its surrounding structures including the muscles. TMD most commonly affects women between the ages of 20-40, but may occur at any age.

Your TMJ is composed of bones, ligaments, articular disc, cartilage, synovial fluid, blood vessels and nerves. Dysfunction or damage to any of these structures can cause pain within your TMJ and the surrounding area. Additionally, when your mouth is closed there is the connection or occlusion of your teeth. Therefore, your dental occlusion (or dental bite) affects the position of your TMJ and the position of your TMJ can also affect your dental occlusion.

Your TMJ attaches your jaw bone to your skull, your skull sits on top of your neck, therefore, changes in your head and neck posture can also affect the function of your TMJ. This also helps to explain why your TMJ pain may be associated with neck pain. In some cases, TMJ pain can be caused specifically by neck pain following trauma such as whiplash.

How does my TMJ work?

The temporomandibular joint connects your jaw bone, called the mandible, to your bone at the side of the head, called the temporal bone. The mandible is a loose bone that depends on a lot of structures to hold it in place. It is easy to feel the movement of your TMJ by placing your fingers just in front of your ear then opening and closing your mouth, you will feel the movement occurring at the joints.

The movement of your TMJ may feel like a simple hinge joint, in fact a variety of complex interactions of sliding, gliding and hinging movements occur at your TMJ enabling you to talk and chew. A strong, important network of muscles surrounds your TMJ to control the movement, these muscles are known as the muscles of mastication.

During mouth opening, the rounded ends (condyles) of mandible rotate and then glide along the temporal bone. The condyles return back to the resting position during mouth closing. A very important structure within your TMJ is the articular disc. The articular disc is attached to the top of the condyle (like a hat sitting on your head) and absorbs shocks to the jaw that occurs during activities such as chewing and biting. Your TMJ joint surfaces are covered by cartilage and the articular disc, which helps to keep the movement of the TMJ smooth.

Painful TMJ disorders can occur if:

• The disc is not sitting within the normal position within the joint
• The joints cartilage is damaged by arthritis
• There is a direct impact to the joint
• Due to Bruxism

Bruxism

This is the term given for grinding the teeth. Bruxism usually occurs at night and often the individual is unaware of this habit. There is some controversy over the causes of bruxism and teeth clenching. One main cause for bruxism is emotional stress, other causes include side effects of certain medications and genetic predisposition. Normally our teeth are in contact for approximately 20 minutes during the day, however, in individuals with bruxism and clenching, the teeth can be in contact for over one hour.

Bruxism can occur both in adults and children. Most people exhibit some bruxist tendencies, however, approximately 10% have symptomatic bruxism leading to jaw pain, headaches, sleep interruption, muscle pain and tooth damage. Headaches and muscle pain associated with bruxism can be successfully treated with Physiotherapy alongside other conservative management options.

Bruxism; this short video demonstrates what happens in patients with bruxist tendencies:

What are the symptoms of TMD?

The most common symptoms of TMD include headaches, jaw and facial pain, ear pain, jaw clicking or grinding, bite shifting or misalignment and limited mouth opening. Other common symptoms include neck and shoulder pain, tooth pain, throat pain, difficulty swallowing, ringing in the ears (tinnitus), dizziness, eye pain, and sinus congestion.

• Aching facial pain
• Pain or aching in and around your ear
• Pain or tenderness of the jaw
• Restricted and painful mouth opening
• Clicking, popping or crunching sounds within the jaw joint
• Headaches
• Pain with chewing or biting
• Neck pain
• Blocked Eustachian tubes (stuffy ears)

Headache

There are numerous causes of headaches, therefore it is essential that you are assessed by a qualified health professional to rule out the more serious and possibly life threatening cause of headaches, especially if it is a first headache or a different type of headache than you are used to. The majority of headaches are not serious.

There are two main broad categories for headaches. Two common types of headaches that are common with TMD are Migraine and Tension-type headache.

Migraine

Migraines usually present as a severe, pulsating one sided pain that is very debilitating. The pain associated with TMD often represents the trigger for a migraine attack. When this occurs, effective Physiotherapy treatment for the TMD is likely to reduce the number of migraine attacks.

Tension-Type Headache

Tension-type headache presents as a constant, steady aching pain and is commonly felt over the forehead region. There are numerous causes of tension-type headache, however one of the more common causes is myofascial pain and can often relate to the muscles surrounding the TMJ and also the neck muscles in TMD sufferers. Successful Physiotherapy treatment of myofascial pain associated with TMD sufferers will reduce the tension-type headache.

Neck pain

Neck pain can result from an acute trauma such as whiplash or chronic stress such as poor posture. Neck pain commonly involves either the cervical vertebrae (neck bones) or the cervical muscles (neck muscles). Less frequently, neck pain can be caused by nerve entrapment or vascular conditions. If you are experiencing any pins and needles, numbness, tingling, nausea, dizziness, changes in vision or speech, then you should be thoroughly assessed to exclude a nerve of vascular cause for your neck pain.

One of the most common causes of persistent neck pain is weakened neck muscles and poor posture. A forward head posture or chin poking commonly causes neck pain due to strain in the cervical muscles. This is a common posture exhibited by most of the population as this posture is commonly observed in those using computers, especially laptops, while driving or sitting at a desk. Pain is commonly felt within the neck and into the shoulders, however facial pain and headaches travelling up the back of the neck are also common symptoms.

Many of the muscles that control the jaw are located at the front of the neck and therefore, pain within these muscles can refer pain in to the face and teeth. The nerves that supply the neck and the jaw join the same region within the brain stem, therefore jaw pain can often cause an increase in neck pain and vice versa.

It is essential that you have a detailed specialist assessment to determine whether your neck pain is due to a TMJ dysfunction or neck dysfunction. Once the cause of your neck pain and TMJ pain is determined, physiotherapy treatment is highly successful.

The position of the TMJ is very close to the ear canal, this helps to explain why TMJ symptoms can include ear pain and also why TMJ pain can masquerade as ear pain.