Disc Displacement (Jaw)

Disc Displacement (Jaw)

Introduction

The jaw is a complex joint, which, like many other joints in the human body, can be subject to pain and injury. There are multiple causes of jaw pain. A displaced disc is one such cause and will be the focus of this blog post.

There is a cartilage disc that lies between the jawbone (mandible) and part of the skull (temporal bone). This disc is attached to multiple ligaments, which allows it to slide forward and backward as the mouth opens and closes. Under normal circumstances, it glides smoothly, acting as a cushion between the mandible and the temporal bone. “Anterior disc displacement” occurs when the disc sits too far forward, potentially causing the mandible to place pressure on other soft tissues instead of the disc.

Symptoms

The following symptoms may be experienced:

  • Jaw pain (potentially severe).
  • Clicking/popping/catching.
  • Jaw locking open (typically in earlier stages).
  • Jaw locking closed (typically in later stages).

 

Assessment

The following assessment methods are relevant to disc displacement:

Postural observation

  • Physiotherapists can tell a lot about muscle activity by observing somebody’s posture. Regarding disc displacement, a slouched, ‘forward head’ posture can indicate that certain muscles around the jaw and neck are overactive (tight) while others are underactive (weak).

Jaw movements

  • Observing various jaw movements can provide a lot of useful information. Some people are excessively mobile, able to open their mouth wider than is ideal, while others will be “locked” and only able to achieve a small degree of opening. Clicking is often heard when assessing jaw opening. Three finger-widths is generally considered to be the normal amount of opening.

Hands-on assessment

  • Hands-on assessment will usually reveal tightness or tenderness of various muscles around the jaw, restricted/excessive mobility of the joint, and abnormal movement and clicking.

Neck assessment

  • The majority of patients with jaw pain also have problems in their neck. A thorough assessment of the neck is therefore appropriate.

Treatment

Fortunately, there are many ways that physiotherapists can treat disc displacement:

Education

  • Jaw pain if often a result of the things that you do every day. You may need to avoid certain foods to minimise stress on your jaw while recovering.
  • Certain habits need to be identified and corrected, such as jaw clenching or nail biting.
  • Adjusting workplace ergonomics is often required. That is, setting up your desk to allow ideal positioning of your neck and jaw.

Postural correction

  • Patients are quick to admit that they slouch all the time, however, they’ve usually never considered what ideal jaw posture looks like. Many patients hold a lot of tension in their jaw and teaching them a few cues can greatly reduce the stress on the joint throughout the day.

Manual therapy (hands-on treatment)

  • Soft tissue techniques (massage).
  • Joint mobilisation.

Dry needling

  • An alternative method to hands-on techniques for treating tight and/or painful muscles.

Exercises

  • The jaw can be exercised like any other body part, leading to improvements in strength, mobility, coordination, and even relaxation.

 Neck treatment

  • Various methods can be used to treat issues at the neck.
  • Often 50% of physiotherapy treatment needs to be directed at the jaw, and the other 50% at the neck.

Finally, it is worth noting that your pain and function can recover by 100%, even though your jaw may continue to click. In other words, jaw clicking can be a normal occurrence, and is only cause for concern if it is accompanied by pain or discomfort.

tmj physio

References

Sato, S., Kawamura, H., Nagasaka, H., & Motegi, K. (1997). The natural course of anterior disc displacement without reduction in the temporomandibular joint: follow-up at 6, 12, and 18 months. Journal of oral and maxillofacial surgery55(3), 234-238.

Shaffer, S. M., Brismée, J. M., Sizer, P. S., & Courtney, C. A. (2014). Temporomandibular disorders. Part 1: anatomy and examination/diagnosis. Journal of manual & manipulative therapy22(1), 2-12.

Shaffer, S. M., Brismée, J. M., Sizer, P. S., & Courtney, C. A. (2014). Temporomandibular disorders. Part 2: conservative management. Journal of Manual & Manipulative Therapy22(1), 13-23.