Benjamin C. Moffett

The effects of continuous passive motion on the temporomandibular joint after surgery

The application of continuous passive motion (CPM) to synovial joints immediately after orthopedic surgery stimulates the regeneration of articular tissue, eliminates adhesions, prevents joint stiffness, reduces pain, and is well tolerated by patients. This article reviews the development of CPM in animal studies and its subsequent clinical applications to patients after orthopedic surgery. It seems likely that CPM applied to the temporomandibular joint after surgery would result in similar advantages to patients. We identify the criteria for the function, patient acceptability, and safety of a CPM appliance to be used on the temporomandibular joint. The first prototype is described and redesigned in a second model that meets the necessary criteria for testing on patients.

Experimentally induced ankylosis and facial asymmetry in the macaque monkey

Six Macaca nemestrina were used for induction of ankylosis by different methods. One TMJ capsule was either (a) mechanically damaged, (b) injected with sodium morrhuate, or (c) injected with a strain of Staphylococcus aureus. The other capsule served as a control. Facial asymmetry of varying degrees was evident from dry-skull preparations and histologically. Sodium morrhuate caused the least degree of alteration; mechanical damage, the most. The effects of Staph. aureus injection into the TMJ seemed to depend upon the length of time elapsed since injection. In one animal there was no change at autopsy after two injections several weeks apart, once on each side; in the other, the capsule injected initially showed no change at autopsy, whereas that injected several weeks prior to autopsy was considerably altered. Induction of ankylosis was achieved with varying degrees of success, causing differing degrees of facial asymmetry.