A critical evaluation of orthopedic interocclusal appliance therapy: design, theory, and overall effectiveness.

Orthopedic interocclusal appliances have been evaluated in a number of research papers and clinical reports over the years. Various theories have been proposed about the method of action of the different appliances, but at present no conclusive controlled testing of these theories has occurred. Certainly, when the potential influence of the nonspecific treatment factors is considered, as well as those cognitive awareness factors common to all appliances, the use of "symptom improvement" as the definitive proof of the need for mandibular realignment or repositioning must be questioned. Specific, well-controlled research using more quantifiable measures of the treatment effect is necessary to make valid comparisons between the different therapeutic approaches. The full-arch occlusal stabilizing appliance is the design that has the most valid evidence about its effectiveness. Partial coverage interocclusal appliances have significant irreversible complications with tooth intrusion or eruption when used on an extended basis. There is little or no experimental support at present about repositioning, realignment, and pivot appliances and their effectiveness. Therefore, these appliances must be considered experimental treatments. When used to treat TM dysfunction in a program along with other methods, such as occlusal adjustments, and prosthetic care, the effectiveness of this treatment method is between 70% and 90%. As a general approach to managing TM pain and dysfunction, interocclusal appliances appear to be a highly effective, commonly used method.