When in Doubt, Cut It Out
When I was invited to speak to the Nebraska Orthodontic Society recently, one of the chief appeals was the opportunity to enjoy a famous Omaha steak, which turned out to be even better than its reputation. However, during the evening I noticed that one of my dinner partners had ordered soup instead of steak. When I inquired about her selection, she told me she was in her second week of recovery from bilateral TMJ replacements. This woman had undergone six unsuccessful surgeries before a decision was made to totally replace both joints with highly sophisticated, computer-designed prostheses.
Six efforts had been made to secure her discs to the condyles, and from her description, they seemed to be standard plication techniques wherein a wedge is removed from the bilaminar layer and the disc is sutured over the condyle. A few years ago plication was a popular technique for resolving painfully clicking joints, which were usually diagnosed as anteriorly displaced discs. Early studies confirmed the usefulness of the method, but lately there have been signs that plication has some serious limitations. Some of its former promoters have even eliminated it from their therapeutic repertoires.
When you think about it, plication does have several drawbacks. Of necessity, it removes part of the retrodiscal tissue--an extremely important source of synovial fluid for both compartments of the joint. This reduces joint lubrication and further restricts joint nutrition and metabolism. It can predispose the patient to degenerative joint disease and increase the danger of adhesions. Plication also reduces the effective elastic component of the superior retrodiscal lamina, which invites restriction of translatory movement or breakdown of the operative site and relapse of the temporomandibular disorder. Lastly, entry into the joint leaves a large amount of scar tissue.
Although the short-term control of joint pain and noise was for the good, the long-term benefits of plication surgery have been more limited. Therefore, dentists are now examining less radical methods of surgical intervention in stubborn TMJ cases. Arthroscopy is gaining adherents, and condylotomy is being reassessed in this country after several decades of successful use in Europe.
A report of a condylotomy case from Drs. George Upton and Steven Sullivan of the University of Michigan is included in this issue of JCO. The technique is not new--it was reported by Kostecka in a 1928 JADA article--but it is an important therapy that deserves more attention from American dentists.
The rationale for subcondylar osteotomy or condylotomy is based on the concept at with the condyle freed from the mandible, e functioning musculature can redistribute he load and permit the condyle to find a more physiologic position through functional readaptation. As with any surgical technique, skill must be exercised, and long-term results are needed before its value can be compared with that of discoplasty, high condylectomy, and discectomy. But Drs. Upton and Sullivan, and others who are using the technique in the United States, are encouraged. Oral surgeons elsewhere must be satisfied with it; after three decades, it is still the preferred TMJ surgical technique in Britain.
There is little doubt that condylotomy is less traumatic and leaves less scarring than surgeries that enter the joint. Nor does it interfere with the anatomy and physiologic functions of the joint, such as disc rotation and translation, pterygoid muscle and retrodiscal counterplay, and metabolism from synovial fluid.
This is not to say that invasive techniques are unnecessary. They are certainly needed to resolve problems such as adhesions, large articular eminences, osteoarthritis, avascular necrosis, chronic hypomobilities, and growth disorders. But we need to understand the rationale, indications, and limitations of any TMJ therapy recommended for our patients, because many of the techniques can have serious, irreversible, and unintended effects--as with my unfortunate dinner partner.
Orthodontists have a continuing responsibility when they refer TMJ patients to oral surgeons. If the surgeon's therapy is ineffective, the orthodontist shares liability. So in addition to a professional interest, we have a definite legal interest in the diagnosis and treatment that someone else recommends for any of our patients.
Patients may benefit from radically invasive TMJ therapies and may even lose all their painful symptoms. But keep in mind that a surgically disturbed temporomandibular joint can never again function entirely normally. It's worth thinking about.