Condylar resorption

Condylar resorption, also known as idiopathic condylar resorption (ICR) or condylysis, is a disorder of the temporomandibular joint where one or both of the mandibular condyles undergo bone resorption. The condition is nine times more common in females than in males and is seen most often in teenagers.

Symptoms can be both aesthetic and functional. They include an anterior open bite, a receding chin, loss of ramus height, antegonial notching, and hyperplasia of the coronoid process. Patients may also experience clicking or popping in the jaw, pain during jaw movement, and limited jaw mobility.

The cause is unknown, though several theories exist. Because it predominantly affects young females, hormonal factors may play a role. Strain on the joint from orthodontic treatment or orthognathic surgery has also been linked to the condition. Additionally, reactive arthritis, rheumatoid arthritis, and psoriatic arthritis are possible contributing causes.

Diagnosis is based on clinical evaluation and imaging, typically cone beam computed tomography. Single-photon emission computed tomography and positron emission tomography are used less often.

Treatment is controversial. Orthodontics alone can correct malocclusion, but results are often unstable or compensatory and do not address aesthetic changes from condylar degeneration. Orthognathic surgery combined with orthodontics can reconstruct and stabilize the condyles and disc, but it does not treat the underlying disease. Meta-analysis indicates that 46–100% of ICR cases treated with orthognathic surgery experience some relapse. Adverse effects of this approach include pain, nerve damage, and loss of sensation due to the location of the inferior alveolar nerve. Anti-inflammatory medications may slow resorption. Arthrocentesis and arthroscopic surgery are sometimes used for disc displacement and other symptoms.

Treatment options vary, and there is no single universally accepted approach. While total joint replacement (TJR) can be effective in severe cases, other treatments such as conservative management and orthognathic surgery are also commonly used to address the condition.