Jaw Locking

Although it is not the most common of TMJ problems, closed lock is very frightening for those who have it. In its most acute stage, the mouth is almost impossible to open because of both a physical block by a displaced disk and significant pain. Because of this, surgery has long been the treatment of choice, since it was assumed that this was the only way to get the disk back in place. However, it was also known that the condition can improve with simple symptom management, or a combination of symptom management and physical therapy. This prompted a group at the University of Minnesota to carry out a randomized clinical trial of four treatments for Closed Lock which we’ve posted for your review below.

Treatment of Closed Lock of the TMJ

A report on a paper by Schiffman, E.L. et al., Journal of Dental Research 86: 58-63, 2007.

In this randomized clinical trial, investigators compared the efficacy of four treatments for Closed Lock:

  • Medical Management (MM): pharmacological treatment of pain and inflammation with anti-inflammatory agents and analgesics
  • Rehabilitation: Combination of MM with dental splints, physical therapy and psychology
  • Arthroscopy: Insertion of a small tube into the joint so that the surgeon can see inside, followed by washing out the joint (aka lavage) and removal of any small pieces of tissue
  • Arthroplasty: Opening of joint so that the surgeon can remove larger pieces of tissue, which could even be the whole TMJ disc, and repairs are made

The scientists used two measures to quantify signs and symptoms, the Craniomandibular Index and Symptom Severity Index. The first measures jaw movement, joint noises, and tenderness of muscles and joints. The second measures the pain – its intensity, tolerability, frequency and duration. They took measurements before treatment began, then at increasing intervals from the end of treatment to five years after treatment.

The main finding was that all four groups were much better three months after treatment. Further, only small improvements occurred out to five years. However, there was no difference between the four groups at any time during the study, which surprised a lot of people.

The authors concluded that, “Primary treatment for patients with closed lock should consist of medical management or rehabilitation.”

We are grateful to Dr. Daniel Laskin, Adjunct Clinical Professor and Chairman Emeritus at Virginia Commonwealth University School of Dentistry, Oral and Maxillofacial Surgery, for his help writing the content in this section.