Sixty-eight years of experimental occlusal interference studies: What havewe learned?

Statement of problem, Understanding is needed regarding the effect that occ lusal interferences have on the teeth, periodontium, and especially on jaw function. Purpose. This article summarizes research in which experimental occlusal in terferences hale been placed on the teeth of animals and human volunteers. Material and Methods. Data from 18 human and 10 animals studies were review ed. Experimental occlusal interferences were grouped into those that alter intercuspal position and those contacting on lateral jan movement only. The outcome of these interferences were analyzed according to their local pulp al-periodontal, jaw function, or bruxism effects. Results. Experimental occlusal interferences in maximum intercuspation had a deleterious effect on periodontal and pulpal tissues of the affected toot h; sometimes this produces a disruption of smooth jaw function and occasion ally jan muscle pain and clicking. Experimental occlusal interferences that contact only in a lateral jaw movement are infrequently harmful to jaw fun ction. Furthermore, no reliable evidence demonstrates that occlusal interfe rences can cause nocturnal bruxism, or stop it. Conclusion. Transient local tooth pain, loosening of the tooth, a slight ch ange in postural muscle tension levels, chewing stroke patterns, and someti mes a clicking joint can be induced by an experimental occlusal interferenc e. Because such findings are present in relatively asymptomatic patients, t hese data do not prove that occlusal interferences are causally related to a chronic jaw muscle pain or temporomandibular joint dysfunction problems.