title: Sixty-eight years of experimental occlusal interference studies: what have we learned?
abstract: BACKGROUND
  Understanding is needed regarding the effect that occlusal interferences have on the teeth, periodontium, and especially on jaw function.
  
  
  OBJECTIVE
  This article summarizes research in which experimental occlusal interferences have been placed on the teeth of animals and human volunteers.
  
  
  METHODS
  Data from 18 human and 10 animals studies were reviewed. Experimental occlusal interferences were grouped into those that alter intercuspal position and those contacting on lateral jaw movement only. The outcome of these interferences were analyzed according to their local pulpal-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 tooth; sometimes this produces a disruption of smooth jaw function and occasionally jaw muscle pain and clicking. Experimental occlusal interferences that contact only in a lateral jaw movement are infrequently harmful to jaw function. Furthermore, no reliable evidence demonstrates that occlusal interferences can cause nocturnal bruxism, or stop it.
  
  
  CONCLUSIONS
  Transient local tooth pain, loosening of the tooth, a slight change in postural muscle tension levels, chewing stroke patterns, and sometimes a clicking joint can be induced by an experimental occlusal interference. Because such findings are present in relatively asymptomatic patients, these data do not prove that occlusal interferences are causally related to a chronic jaw muscle pain or temporomandibular joint dysfunction problems.
authors.affiliation: School of Dentistry, University of California, Los Angeles, CA 90095-1668, USA. glennc@dent.ucla.edu
authors.forename: G T
authors.initials: GT
authors.lastname: Clark
authors.forename: Y
authors.initials: Y
authors.lastname: Tsukiyama
authors.forename: K
authors.initials: K
authors.lastname: Baba
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D002012:Bruxism / Q000209:etiology; D003481:Cuspid / Q000502:physiology; D003769:Dental Occlusion, Traumatic / Q000150:complications / Q000503:physiopathology*; D003788:Dental Pulp Diseases / Q000209:etiology; D006801:Humans; D008334:Mandible / Q000503:physiopathology; D017622:Periodontal Attachment Loss / Q000209:etiology; D013705:Temporomandibular Joint Disorders / Q000209:etiology; D014086:Tooth Mobility / Q000209:etiology; D014716:Vertical Dimension