Reducible disc displacement of the temporomandibular joint (TMJ)

What is reducible disc displacement?

The temporomandibular joint (TMJ) connects the lower jaw to the skull. Between the two articular surfaces lies a small cartilage disc that acts as a shock absorber during jaw movements.

In some people, this disc shifts slightly forward when the mouth is closed. On opening, the disc returns to its normal position, producing a clicking or “click” sound. This is known as reducible disc displacement.

This situation is common and is not considered a serious disease.

What are the symptoms?

The most common signs are:

• Clicking or joint noise when opening and/or closing the mouth.
• A sensation that the jaw “jumps” or repositions itself.
• Fatigue of the chewing muscles.
• A feeling of tension in the temples, cheeks or in front of the ear.
• Occasional pain when chewing.

Many people have joint clicking without any pain or functional limitation.

How common is the problem?

Joint noises are very common in the general population.

Studies show that:

• Up to 30 to 50% of adults experience joint clicking at some point in their lives.
• A large proportion of those affected feel no pain.
• The majority of cases remain stable for many years.

The presence of isolated clicking does not mean that the joint will necessarily deteriorate.

What should be avoided?

When a joint is painful or irritated, it is advisable to temporarily limit:

• Chewing gum.
• Very hard foods (very crusty baguette, nuts, hard sweets).
• Foods requiring a wide mouth opening.
• Biting on pens, nails or objects.
• Excessive yawning without supporting the jaw.
• Clenching or grinding of the teeth (bruxism) when identified.

Which treatments are recommended?

Current scientific recommendations favour conservative treatments.

Understanding how the joint works often helps to reduce anxiety and the associated muscle tension.

Simple joint clicking without pain or limitation of opening generally requires no treatment.

1. Self-care measures

The following measures are often effective:

• A soft diet during painful periods.
• Limiting extreme opening movements.
• Applying local heat.
• Muscle relaxation exercises.
• Correcting daytime teeth-clenching habits.

2. Specialised physiotherapy

Oro-maxillofacial physiotherapy can help to:

• Improve mandibular mobility.
• Reduce muscle tension.
• Learn suitable exercises.
• Improve control of jaw movements.

4. Medication

In cases of significant pain, your practitioner may temporarily recommend:

• Anti-inflammatories.
• Painkillers.
• Muscle relaxants.

These treatments do not correct the position of the disc but help to reduce inflammation and pain and facilitate jaw mobility.

5. Botulinum toxin injections

In cases where patients have very significant teeth clenching (bruxism: with wear or fractures of the teeth; clenching: clenching only), including at night, the volume of the masseter muscles (in the cheek) can become large and painful.

In some situations, these patients may also prematurely break or damage an occlusal splint. It is therefore recommended to perform botulinum toxin injections to relax the masseter muscles and to avoid excessive pressure on the teeth and joints.

6. Is surgical treatment necessary?

In the vast majority of cases, no.

Surgical or arthroscopic treatments are reserved for particular situations with advanced symptoms.

Simple joint clicking is generally not an indication for surgery.

What is the prognosis?

Reducible disc displacement most often has a favourable course.

Many patients keep a slight clicking for years without any impact on their quality of life or on the function of their jaw.

The aim of treatment is mainly to control pain and to preserve normal joint function.