Why Does it Hurt When I Chew Food (Or Open My Mouth)

Our body usually performs beautifully, often without our awareness-unless something goes wrong. The temporomandibular joint (TMJ), or jaw joint is a great example.

Your Temporomandibular Joint , is the most used joint articulation in the body. Your TMJs (jaw joints) are involved with eating, talking, breathing and, probably most importantly, expressing your feelings and emotions. When things go wrong with your TMJ, it is known as Temporomandibular Disorder (TMD). (1)

TMD is a common condition, signs of which appear in up to 60–70% of the population.(1) The peak incidence is seen in adults aged 20–40 years. Women are at least four times as likely to suffer from the disorder.(3) TMD can be annoying and persistent or acutely disabling.

Treatment of the jaw for pain, clicking and locking can be challenging. We often get referrals from dental specialists for patients with prolonged or acute temporomandibular pain and restricted movement.


The Temporomandibular Joint (TMJ) complex consists of two joints on either side between the skull and jaw bone. There is small fibrous shock absorbing disc within the joint that needs to shift correctly for normal pain free jaw movements such as opening and closing your mouth, yawning and chewing. There are many small muscles that are involved in ensuring smooth, precise TMJ movement, and can contribute to increased strain in the joint.


You may or may not experience jaw pain or tenderness with TMJ dysfunction. The most common symptoms include:
• jaw clicking
• grinding
• limited jaw opening, or jaw deviation while opening
• an inability to fully clench your jaw. (1)

TMD sufferers are often teeth grinders or clenchers. TMD can cause jaw headaches, ear pain, dizziness and neck pain. Some TMJ patients report pain or inability to eat, talk or sing. Tinnitus or ear ringing can be associated with TMJ dysfunction.

Causes of TMD

Successful management of TMD involves identifying and managing contributing factors.1 It is important to distinguish between muscle related causes of TMD and intra-articular disorders of the joint itself. TMJ pain may also be caused by referral from the neck or more remote areas. Muscle related disorders are the result of tension, fatigue or spasm of the masticatory (chewing) muscles, whereas intra-articular disorder stems from mechanical or inflammatory disruption of the joint itself.
Soft tissue dysfunction is the most common cause of TMD. Teeth grinding, clenching and abnormal posture, stress and anxiety, may all contribute to masticatory muscle pain and spasm. Cognitive and psychiatric disturbance, such as depression and anxiety, and autoimmune disorders, fibromyalgia and other chronic pain conditions are also frequently associated with TMD and may be a part regional pain syndrome.
Intra-articular causes of TMD include internal joint derangement, osteoarthritis, hypermobility and traumatic injury. Inflammatory conditions, such as rheumatoid arthritis may lead to internal joint derangement. Articular disc displacement from the normal position is the most common joint related cause of TMD. In our experience careful assessment often reveals stiffness in the joint gliding.(2)


Physiotherapy has been shown to be effective in the management of TMD, especially with regards to improving joint range of motion.(4)
Behaviour modifications, including improving sleep hygiene, stress reduction and elimination of bad habits such as teeth clenching and grinding, are particularly important.
A careful, comprehensive assessment of the joint and the muscles that control movement: some which are internal and difficult to access is essential to find and treat the dysfunctions that cause pain and disordered movement. Close examination of the neck, upper back and posture is also important in order to get best results. A structured home exercise program is essential.

If you have pain or disturbed movement in your jaw area or persistent headaches, you need to have an TMJ assessment as part of a comprehensive treatment approach. At Northwest Physiotherapy Group we look at the whole body to find and treat the main contributors of your pain.


  1. https://physioworks.com.au/pain-injury/jaw-pain-tmj-pain/tmj_dysfunction/
  2. https://www1.racgp.org.au/ajgp/2018/april/temporomandibular-dysfunction
  3. Sharma S, Gupta DS, Pal US, Jurel SK. Etiological factors of temporomandibular joint disorders. Natl J Maxillofac Surg 2011;2(2):116–19. doi: 10.4103/0975-5950.94463. Search PubMed
  4. Ahmed N, Poate T, Nacher-Garcia C, et al. Temporomandibular joint multidisciplinary team clinic. Br J Oral Maxillofac Surg 2014;52(9):827−30. doi: 10.1016/j.bjoms.2014.07.254. Search PubMed
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