Temporomandibular joint, showing TMJ disc.The National Institutes of Health have awarded Kyriacos Athanasiou, a Distinguished Professor of Biomedical Engineering and Orthopaedic Surgery at the University of California, Davis, a $1.87 million grant to continue his work on temporomandibular joint (TMJ) disc regeneration. The five-year project is a collaboration with the University of Texas Medical School at Houston.

The temporomandibular joint brings the jaw bone, or mandible, together with the cranium, or skull, over a small disc of cartilage attached to the bone known as the “articular disc.” The disc allows the mandible to slide smoothly and painlessly up and down, sideways, and in a circular motion against the skull. This makes speaking and chewing possible.

Approximately 10 million people in the U.S. suffer from TMJ disorders. The most common disorder occurs when the disc’s attachments malfunction and the disc slips out of place. The bones no longer move smoothly against each other, causing pain and difficulty chewing.  Popping or clicking sounds may be heard as the bones pop in and out of place during chewing or talking. The displacement proceeds to perforation and thinning of the disc, and ultimately, arthritis and degeneration of the entire joint.

Unfortunately, few treatments exist for disc degeneration. Professor Athanasiou’s lab used funding from an earlier NIH grant to develop a method to grow TMJ cartilage discs in the lab. The current project will investigate the mechanisms that attach the disc to the bone and will engineer an anatomically-shaped, biomimetic TMJ disc complex (disc plus attachments) suitable toward the treatment of several TMJ problems. The biomimetic TMJ disc complex can be trimmed to fit a variety of defects in the joint.

This will be the first time scientists  create a TMJ disc complex that incorporates the anatomically-correct disc shape. The project will also set design standards for engineering the various TMJ attachments, about which little is currently known.