The temporomandibular joint (TMJ) is essential for speech and mastication. When it is damaged or diseased, the ability to enjoy food and to speak with confidence is reduced, whilst changes in the facial aesthetics can increase self-consciousness. Quality of life is therefore impacted, prompting the need for a greater understanding of the risk factors of a temporomandibular disorder (TMD).
Condylar joints are found across the body, from the wrists to the toes, and allow flexion, extension, abduction and adduction movements. The TMJ is connected to two condyles; these allow the lower jaw to pivot for talking, eating and breathing. Damage to the condyle damages the TMJ. Condylar resorption is thus associated with TMD, particularly TMJ arthralgia, and dental practitioners should be encouraged to identify its risk factors and know how to treat it, helping at-risk patients live a happier life.
Knowing the causes
Condylar resorption causes the mandibular condyles to break down, leading to bone loss and shortening the posterior part of the face. It can be noticeable for the patient; they may observe that their lower jaw has shrunk or retracted, leading to a change in their bite. The condition is rare, but has many risk factors:
- Autoimmune diseases, such as rheumatoid arthritis
- Avascular necrosis
- Infection in the TMJ
- Orthodontic treatment, or other treatments that impact TMJ loading
- Trauma to the TMJ
Another risk factor is hormonal changes and, connected with this, age. Condylar resorption is nine times more common in women than in men, with a high prevalence for those aged between 10-20. Along with adolescence, pregnancy and other hormonal changes are also associated with disease activity flare-ups, though the condylar resorption can also be spontaneous.
Changes in the jaw
Around 60 to 70 per cent of the UK population will experience some form of TMD in their lifetime. Two per cent of people with TMD will also report a limitation with opening their jaw, leading to extended pain and impaired function. Condylar resorption is a dominant factor for the closed lock of the TMJ, making it an essential risk for practitioners to help vulnerable patients with.
The progression of degenerative joint disorders, such as osteoarthritis, leads to changes in the condyle, such as flattening and erosion. In a case study of TMJ arthralgia, 59.6 per cent of cases also had condylar erosion, whilst among asymptomatic patients only 21.2 per cent had it. A grade III condylar erosion leads to a high increase in the risk of TMJ arthralgia, inflaming the joints. This can cause notable joint sounds, headaches pain, and irregular or deviating jaw function.
As changes in the condyle alter the TMJ, condyle resorption can lead to malocclusion. An unstable occlusion can disrupt load-bearing capacity, further contributing to TMD and restricted jaw opening. Not only is a malocclusion painful and detrimental to aesthetics, but it can also increase the risk of tooth decay and tooth loss.
Diagnosis referral
To lower the risk of decay and tooth loss, practitioners should consider recommending at-risk patients for an assessment of condylar resorption so that it can be managed before there are changes to the dentofacial morphology and, for adolescent patients, to ensure mandibular growth continues uninterrupted.
For a diagnosis, a medical professional will take cone beam computed tomography (CBCT) scans of the TMJs to visualise the key features of condylar resorption. There are many factors to consider, including the history of the patient, the family history of autoimmune diseases, lifestyle choices, and medications – dental practitioners can identify some of these beforehand. From there, the patient can be guided to the various ways of managing the disease. This can include anti-inflammatory medications, along with bite splints or night guards to prevent further mechanical damage from bruxism. For longer-term solutions, orthodontic treatment can correct malocclusions, and orthognathic surgery can align the maxilla and mandible for an improved bite.
Open wide
TMDs can be painful, affecting mood and lowering a patient’s quality of life. For an excellent physical therapy solution, recommend the OraStretch Press Jaw Rehab System from Total TMJ. The hand-operated device is user-operated; a simple squeeze of the handles stretches the oral cavity to mobilise the TMJ. When abiding by the suggested treatment instructions, the device improves jaw function, reducing pain and restoring strength. With a transportable solution like this, patients can be empowered to control their health and return to a better quality of life.
Condylar resorption is rare but impactful, with further research needed to better understand its aetiology. As a risk factor for TMD and malocclusion, it is vital that practitioners expand their knowledge of condylar resorption so that they can aid effected or at-risk patients, and reduce the risk of TMJ dysfunction.
References available on request.
For more information email info@totaltmj.co.uk