Hermione Halman

Welcome back, 2020 wasn’t what anyone expected and I hope you’re all doing well. Adapting to change is hard but we made it and hopefully, there is hope at the end of the tunnel, in the form of the vaccine and a more social 2021. 

Today’s blog is part of the ‘top to toe’ series I started last year, we have focused on headaches thus far and general ways to combat and manage symptoms. As always if you are concerned about your health please consult your doctor or book to see your local osteopath. 

TMJ anatomy

Today we will be looking at the Temporomandibular joint or ‘TMJ’, the joint that forms your jaw.  As the name suggests the joint is formed of the temporal bone located at the side of the skull and the mandible (jaw bone)(Figure 1). An articular disc is located between these surfaces preventing the articulating bones from coming into contact with one another, cushioning the joint, and providing a smooth movement (Figure 2).

Figure 1: Illustration of the TMJ and bones forming the joint

Figure 2: Cross-section of the TMJ indicating the articular disc and joint structure

The TMJ is capable of 3 sets of movement patterns, elevation and depression, opening and closing the mouth (Figure 3), protrusion, and retraction, the action of pushing out the jaw and pulling it back (Figure 4), side translation, moving the jaw from side to side (Figure 5).

Figure 3.a: Illustration of jaw closed

Figure 3.b: Illustration of jaw slightly open

Figure 3.c: Illustration of jaw wide open 

As illustrated in figure 3.c, you can see that when the jaw is opened wide, there is a slight forward glide of the mandibular head within the joint.

Figure 4.a Illustration of protraction of the mandible (pushing the jaw forward)

Figure 4.b Illustration of retraction of the mandible (pulling jaw backwards)

Figure 5. Illustration of anatomical TMJ side shift

The function of the jaw is controlled and supported by surrounding musculature and a network of ligaments, the 3 main ligaments include lateral temporomandibular ligament, sphenomandibular ligament, and the stylomandibular ligament (Figure 6). 

Figure 6. Illustration of TMJ ligaments.

We call the muscles used for chewing, the muscles of mastication. These muscles are; Masseter, Temporalis (Figure 7), and medial and lateral Pterygoid (Figure 8) which all have their specific functions. 

Masseter: Elevation of the mandible

Temporalis: Elevation and retraction of the mandible.

Figure 7. Illustration of Masseter and Temporalis muscles

Medial Pterygoid: Elevation of the mandible

Lateral Pterygoid: working together: protraction and individually: Side shift. 

Figure 8. Illustration of Medial and Lateral Pterygoid muscles

Clinical Presentations:

Patients may come to us for clicking, locking, or pain when eating or talking, general tension in the jaw and side of the head, or headaches. 

There is a multitude of different factors that may indicate a TMJ dysfunction or reason for pain. A few factors I have identified and continue to look out for in the clinic are stress, previous or current orthodontic treatment, muscle tension in the jaw or upper neck, and trigger points. 

Stress: Patients often report clenching or grinding of teeth as a result. They can also present with general tension of the neck and shoulders. 

Previous or current orthodontic treatment: presentation includes feeling a click or discomfort in usually one side of the jaw when eating. The changes in alignment and bite of teeth following orthodontic treatment can alter the tension in one or both sides of the jaw. The body often takes some time to adapt and this change can be a contributing factor to TMJ discomfort or pain. 

Neck and jaw muscle tension: It is a common finding that if the upper segment of the spine is tighter than usual, the TMJ can be affected and vice versa. This is due to their anatomical relationship with one another. Muscles can become fatigued if they are working too hard or compensating for restriction. 

As also mentioned in the ‘Headaches post, trigger points in the muscles of mastication may also lead to TMJ discomfort.

Treatment

Treatment of the TMJ includes holistic assessment and treatment of the jaw, neck, upper back, and shoulders. By using a mixture of techniques such as joint mobilisation and soft tissue work, along with mobility and stretch exercises we can try to help reduce symptoms. 

Please note that to access the ligaments and pterygoid muscles your osteopath may need to work inside the mouth.

Patients presenting with jaw dysfunction and or pain often benefit from seeing their dentist who will be able to more specifically assess the teeth and jaw and may be able to fit a mouthguard if necessary to reduce tension from grinding and clenching during the night. 

The above-mentioned presentations are not extensive of the causes of jaw pain but are the more common presentations seen in the clinic.

If you are experiencing discomfort, book to see your dentist and or local osteopath and we will be able to assess and guide you.

If anyone has any questions please leave them below.

Take Care, 

Hermione