Jaw Pain – Understanding the TMJ

The Temporomandibular Joint (TMJ) is a complex joint that enables us to eat, chew and speak. The TMJ can be a source of pain and dysfunction for many individuals. Although not a common presentation in the Physiotherapy clinic for those with TMJ pain it can be a significant source of pain and disability. It predominately occurs between 30-50 years of age and has a higher incidence of female. TMJ disorders may be present in up to 60% of the population, although few seek treatment (1).

TMJ Anatomy

The TMJ is composed of articular surface of the mandibular condyle and mandibular fossa of the temporal bone. The two compartments (upper and lower) separated by an articular disc (fibrocartilaginous). The articular disc attaches anteriorly to the lateral pterygoid (muscle) and posteriorly to the joint capsule and connective tissue. The disc is avascualar and aneural and thus is not a pain source for TMJ pain (2).

The intra-articular area posterior to the disc is called the retrodiscal area or bilaminar zone. It consists of blood vessels (high vascularity), synovial membrane, nerves and loose CT structures. This area can become symptom source with TMJ pain.

The musculature of the Jaw is also complex and outlined below are the muscles of the TMJ and their actions:

• Elevators of the Jaw: Masseter, Medial pterygoid, Temporalis
• Depressors of the Jaw: Lateral pterygoid, Digastric and hyoids
• Protrusion (Poking forward): Masseter and pterygoids
• Retrusion (Drawing in): Temporalis, digastric and hyoids

These muscles work to produce functions such as chewing, speaking, swallowing, breathing and secondary function of bruxing. Bruxing refers to the grinding, nashing of teeth with or without teeth closure. It is a major factor in the development of TMJ disorders, significantly increased by stress.

Signs and Symptoms of TMJ Disorders

TMJ disorders can present with pain in the neck, face (noteably around the jaw), ears or teeth. Clients often describe fullness or ringing in their ears, lateral or posterior headaches, joint sounds and limitations in jaw movment. It is important to look out for a history of trauma – minor, major or affecting the cervical spine, as TMJ pain can be referred from the cervical spine. TMJ disorders can also follow oral surgery such as tooth extraction, jaw reshaping or dentistry. In some circumstances it can occur insidiously or with possible emotional or stressful events and illness. Physical assessment including palpation, observation of movement , joint glides and muscle strength testing.

Some good questions that indicate there could be a TMJ problem include (3):

• Do you hear joint sounds?
• Do you have limitation in mouth opening?
• Do you have pain in or about the ears?
• Have you ever had joint locking?
• Do you have pain on chewing?
• Have you ever had trauma to head and neck area? If yes, how many times?
• Do you have stress, or under stressful conditions?
• Do you have pain in other joints in your body?

Grouping of TMJ Disorders

1. Joint disorders

• Derangement of condyle/disc complex – a common cause of TMJ problems that results in altered movement of the articular disc which can lead to clicking, locking and difficulty in various stages of jaw opening and closing (3).
• Dislocation
• Joint surface problem
• Inflammation or inflammatory

2. Masticatory muscle disorders – commonly attributable to myofascial pain: muscle tenderness points on palpation, worse with stress, often associated with bruxing and may have other chronic pain state.
3. Chronic hypomobility – Bony or soft tissue
4. Growth disorders – Asymmetrical jaw can predispose to displacement

Management

Goals of treatment include:
1. Decreasing joint pain
2. Increasing joint function and opening
3. Preventing further joint damage
4. Improving overall quality of life and reducing disease-related morbidities

Management of TMJ disorders aims to be conservative (non-surgical). This may include splints, education regarding pain relief options such as posture changes, relaxation techniques, food modifications and medication. Physiotherapy is commonly used in the outpatient setting to relieve musculoskeletal pain, reduce inflammation, and restore oral motor function. It plays an adjunctive role in virtually all TMJ disorders treatment regimens. Although the evidence is weak, there are numerous systematic review articles that support the efficacy of exercise therapy, thermal therapy, and acupuncture to reduce symptoms, such as pain, swelling, and TMJ hypomobility (4-5).

Physiotherapy techniques can include manual therapy to improve joint range of movement, postural exercises, muscle stretching, and strengthening exercises. Passive and active stretching of muscles or range-of-motion exercises are performed to increase oral opening and decrease pain.

If unresponsive to conservative management alternatives include cortisone injections, arthroscopy and joint replacement. These interventions have to fulfil specific indications and are usually reserved for more severe joint anatomical abnormalities (3).

Lewis Craig (APAM)
POGO Physiotherapist
Masters of Physiotherapy

Featured in the Top 50 Physical Therapy Blog

References

1) Okeson JP. Management of Temporomandibular Disorders and Occlusion (ed 3). St. Louis
2) Piette, E. (1993). Anatomy of the human temporomandibular joint. An updated comprehensive review. Acta Stomatologica Belgica, 90(2), 103-127.
3) Liu, F., & Steinkeler, A. (2013). Epidemiology, diagnosis, and treatment of temporomandibular disorders. Dental Clinics of North America, 57(3), 465-479.
4) McNeely ML, Armijo Olivo S, Magee DJ. A systematic review of the effectiveness of physical therapy interventions for temporomandibular disorders. Phys Ther 2006;86(5):710–25.
5) Cho SH, Whang WW. Acupuncture for temporomandibular disorders: a systematic review. J Orofac Pain 2010;24(2):152–62.

Subscribe to our newsletter

Never miss a podcast or blog post when you subscribe to our weekly newsletter. The podcast features interviews with the world’s leading physical performers, and some of the world’s leading health and fitness experts.

SUBSCRIBE!

You have Successfully Subscribed!

Your email is safe with us, and you can opt out at any time.