Open joint surgery is more of a descriptive term for access of the TMJ rather than a specific procedure. An incision is made by the ear and Dr. Bobek can access the joint to address a number of issues. It is an outpatient surgery offered to people who cannot be improved with less invasive techniques (injection or arthroscopy) and don’t want more invasive techniques (tmj replacement.)
Here are common questions in regards to this procedure
Much like other TMJ surgeries, a clinical exam and MRI are useful for determining if open surgery is right for you. For most people with a painful joint and limited function, nonsurgical techniques are still best. But if you are not improving, have severe arthritis, or have other noninternal derangement problems, open joint surgery might be right for you.
There are more groups of people who benefit from open surgery than arthroscopy. Here are the clinical situations where open joint surgery makes sense.
This is a procedure to reapproximate the disc between the condyle and the fossa. Typically used for moderate to severe internal derangement, this allows for the disc to be anchored to the condyle. The video at the start of this page shows this surgery. Metal anchors (mitek) are not used now as they make future MRI evaluation difficult. Dr. Bobek utilizes a juggerknot suture anchor to better anchor the disc.
This is a more typical procedure for TMJ arthritis. Much like a meniscus removal from a knee, the TMJ disc is removed to allow for better mobility in situations with advanced arthritis. A common alternative is TMJ replacement. With removal of the disc, the condyle can move more freely along the skull (fossa), improving mouth opening and pain. Bone spurs can be smoothed and the joint recontoured. Dr. Bobek most frequently uses abdominal fat to graft the space left by removal of the disc. This is to reduce the risk of ankylosis, or fusion of the joint. Other materials used include dermis or temporalis muscle. These are not preferred at Seattle Jaw surgery but are used in some unusual situations.
The eminence, is the prominence of the skull that the jaw slides down when you open your mouth widely. Some peoples jaw gets trapped in front of the eminence, a situation called joint dislocation. Frequently people need to go to the emergency room or an emergency dentist to relocate the jaw back behind the eminence. TMJ dislocation can be a chronic condition that is best treated with the removal of the eminence, a procedure called eminectomy. This is a reduction or removal of the eminence so that the jaw (condyle) doesn’t get trapped and the jaw doesn’t get stuck dislocated. A more conservative alternative to this are blood injections.
Sometimes there are growth abnormalities in the condylar head. In younger people, that condition is known as condylar hyperplasia. With condylar hyperplasia, the jaw grows very asymmetrically after the persons growth is otherwise complete. In older people, it is known as an osteochondroma. Treatment of active condylar hyperplasia and some osteochondromas is with removal of part of the condyle. This procedure is known as a condyletomy. Partial removal of the condyle allows for removal of the growth center and improvement in the condyle contours. The disc is secured to the reduced condyle with a juggerknot. This procedure is most commonly done with orthognathic surgery to maintain the way the teeth fit.
Most benign joint tumors are most easily accessed via an open joint surgery. Removal of synovial chondromatosis (joint mice), osteochondromas, pigmented villonodular synovitis, chondromas, osteomas, or even joint cysts can be done via an open approach. These are rare lesions but are safely removed via this surgery.
Jaw fractures can happen anywhere from the chin to the jaw joint. Jaw joint fractures are known as condylar or subcondylar fractures. Jaw joint fractures can be treated with your teeth wired shut or with surgery to align the broken bone and place plates and screws to hold the bone together. Given the unique anatomy of the TMJ, some fractures cause the condyle to be pulled out of the socket, a condition called a fracture dislocation. These are best managed with surgery and open joint surgery allows the disc to be appropriately positioned between the condyle and skull (fossa). Unfortunately, some people with this injury are treated with wiring of the teeth shut (closed reduction.) We use the open approach to the TMJ to help those people with either joint replacement or a condylar osteotomy.
This is a surgery that is largely the same as removal of the disc and fat grafting. The difference is that a gap arthroplasty is seen as an alternative to joint replacement for fibrous or bony ankylosis. This can be useful in patients without teeth or who cannot receive a joint replacement.
TMJ infections, while rare, do happen. These are typically surgical situations due to the proximity of the joint to the brain. Sometimes infections can be managed arthroscopically but not always. With TMJ replacement devices, managing early infections is done with a DAIR protocol. Extra bone that grows over the TMJ device (heterotopic bone) can also be removed via open TMJ surgery.
This is an unusual problem caused by a patent Foramen Tympanicum (Huschke.) Approximately 1-3% of all people have this but a much smaller percent of people have problems with it. The classic symptom is that your hearing is muffled when you bite into food. Typically diagnosed by ENT (ear nose and throat) doctors, this problem can be repaired with a simple cartilage graft.
A hole in the right disc as seen from the side.
Absolutely. Like all other TMJ surgeries, you should try to get better with more conservative approaches. Common ones include jaw rest, medication, physical therapy, or even splint therapy. In terms of surgery, a good alternative to arthroscopy is injection therapy.
The most common risk with an open TMJ arthroplasty is scarring. Scarring can limit motion and cause pain. Pain or limitation in movement following surgery is always a risk so we have you limit chewing and liberalize movement following this surgery. Physical therapy is very important in recovery. Even with good physical therapy the scarring can be such that more surgery or injections are needed.
Another risk with this surgery is that the way your teeth fit can change. If it is one sided surgery where the disc is removed or a tumor is removed, the teeth on the side of surgery tend to hit first. If the disc is repositioned the other side of the mouths teeth hit first. Most people manage this with general dentistry (adding to or trimming teeth) or braces. Rarely, the way the teeth fit is bad enough to discuss jaw surgery.
You do need physical therapy. Physical therapy helps keep your joint moving after the scar is removed or the capsule is released.
Face weakness, change in occlusion, and face numbness are other more rare risks.
TMJ disorders are seldom “fixed”. Unfortunately they flare up from time to time. Open TMJ arthroplasty is a surgical technique to help you adapt to the different anatomy in the joint and manage longer term flare ups. The surgery increases the space for your jaw to move. All of these can help with pain and movement of the joint, but they do not “fix” the joint.
Picture of an ear canal with the mouth open (left) and closed (right). Herniation of the TMJ into the ear canal is seen as the pink dome on the right.
