There are a number of local and systemic factors or diseases that may lead to mandibular condylar resorption. Local factors include ICR, osteoarthritis, reactive arthritis, avascular necrosis, infection, and traumatic injuries. Systemic connective tissue and autoimmune diseases that can create condylar resorption include: rheumatoid arthritis, psoriatic arthritis, scleroderma, systemic lupus erythematosus, Sjögren’s syndrome, and ankylosing spondylitis. ICR can create occlusal and skeletal instability, dentofacial deformities, TMJ dysfunction, and pain.
Medical management standards for ICR have yet to be established that will provide predictable stable outcomes for the TMJ, provide optimal functional andesthetic results, and eliminate pain. Previously described options for the treatment of ICR include: (1) splint therapy to minimize joint loading; (2) “nonloading” orthodontic and orthognathic surgical procedures after 6 to 12 months of remission; (3) deferment of treatment until ICR remission; (4) arthroscopic lysis and lavage; (5) condylar replacement with a costochondral graft if the ICR cannot be controlled or recurs; and (6) maxillary surgery only to correct the occlusal deformity.
When it comes to managing ICR with Physical Therapy, choices 1 through 6 are not in our tool box. I continue to see more and more cases of ICR in my female more than male patients. In my experience, clients are in mid orthodontic treatment when they tend to come to me for treatment. There is no strong evidence that I am aware of that orthodontics causes ICR, I believe it to be just an unfortunate coincidence or timing issue. I do wonder, however, if Physical Therapists skilled in treating the TMJ and Orthodontists worked closer together, and screened any highly suspect teenagers, we might pick up ICR prior to going into braces. The typical scenario of a client with ICR that presents to my clinic are as follows:
- Complaints of TMJ pain with functional activities like yawning, chewing, etc.
- Intermittent locking, or in some cases present with a closed lock or disc displacement without reduction, or just crepitus
- Pain and trigger points in muscles of mastication
- Midline shift of the mandible
The mandibular shift might indicate a loss of condylar height (the mandible tends to shift to the side of condylar height loss, or in cases where there is bilateral ICR I then observe various stages of an anterior open bite).
If I observe the above findings, then suggest the client receive a cone beam scan which I have found to be excellent for assessing boney and joint related changes, including ICR. I then work closely with the referring dentist or orthodontist to determine the best treatment. In some cases, if they have braces on when we discover ICR, the doctor will remove the braces. Or, they may leave the braces on but remove any bands, etc that might add to additional TMJ compression. If braces are removed, I will work with the other care team members to determine if splint fabrication is appropriate to add vertical dimension or reduce joint compression.
From a physical therapy perspective, I try to keep it simple. I attempt to reduce pain with various modalities and gentle manual techniques. I may work with a compounding pharmacy to create an anti-inflammatory and pain relieving ointment the patient can rub on the affected area. Or, work with their medical team to recommend an NSAID or suitable alternative. I proceed manually to treat involved muscles of mastication with massage intraorally and extraorally, as well as dry needling to active trigger points. If joint mechanics are affected, gentle mobilization techniques are performed to restore pain free, functional TMJ movement. I also include treatment for any related cervical or postural issues. I then educate the client on self-care to control pain and reduce TMJ compressive forces including:
- Eating steamed not fresh vegetables
- Taking small, tender bites of food
- Avoid parafunctional activities like nail biting
- Even consider a short course of a liquid only diet if very acute
- Limit yawning opening to avoid subluxation
- Moist heat or ice application, depending on what stage and symptoms they present with.
I have not witnessed a patient who needed to go onto surgical intervention as indicated earlier. I have found physical therapy to be a very effective option for patient with ICR. In a perfect world, patients are best served when physical therapists, dental professionals, and at times a speech therapist, massage therapist, or dental hygienist trained in myofunctional therapy are able to work together.
Below I have included some pictures to indicate what ICR might look like on a cone beam scan, representation of a midline shift of the mandible and an anterior open bite.
Copyright 2013 by Mosby an imprint of Elsevier Inc.
A: Sometimes significant osteoarthritic changes occur in only one joint. When this happens rapidly, the affected condyle can collapse, resulting in a shifting of the mandible to that side. This is referred to as idiopathic condylar resorption.
B: In this patient there has been a midline shift to the patient’s right. This shift is evident even in the relationships of the posterior arches. This idiopathic condylar resorption was isolated to the patient’s right condyle.
C: A cone beam CT of the right condyle showing the degenerative changes.
D: The loss of condylar support in the right condyle caused a shift to the right, so that only the right second molar is contacting.
Copyright 2013 by Mosby an imprint of Elsevier Inc.
Rheumatoid arthritis commonly causes a significant and relatively rapid loss of the articular bone of both condyles. With this loss of posterior support to the mandible, the posterior teeth begin to contact heavily. These teeth act as fulcrums by which the mandible rotates, collapsing posteriorly and opening anteriorly. The result is an anterior open bite.
Both of these images and text are taken from Dr. Jeff Okeson’s wonderful book entitled: Management of Temoromandibular Disorders and Occlusion by Jeff Okeson, 7th edition, 2013.
It is my pleasure to work with TMJ patients and collaborate with providers. Please let me know what successes you have had with idiopathic condylar resorption.