title: Occlusal changes following posterior tooth loss in adults. Part 3. A study of clinical parameters associated with the presence of occlusal interferences following posterior tooth loss.
abstract: OBJECTIVE
  Tooth positional changes following posterior tooth loss may alter arch forms and occlusal planes. This may result in the development of occlusal interferences. The purpose of this study was to determine clinical parameters associated with the presence of retruded contact position (RCP) contacts and occlusal interferences associated with posterior tooth loss.
  
  
  METHODS
  Diagnostic casts of 100 patients with at least one unopposed posterior tooth and 100 control patients were scanned and analyzed to record clinical parameters described in the earlier publications in this series. Clinical examinations identified the presence of RCP contacts and occlusal interferences. Five generalized linear models were developed to investigate the parameters associated with presence of RCP contacts, protrusive interferences, working side interferences, and nonworking side interferences.
  
  
  RESULTS
  RCP contacts were associated with the degree of supraeruption of the unopposed tooth and the presence of other types of interferences. Protrusive interferences were associated with the presence and position of a tooth distal to the extraction site and the presence of other types of interference. Working side interferences were associated with tipping of the tooth mesial to the extraction site and the presence of other interferences. Nonworking side interferences were associated with the presence of other types of interference only.
  
  
  CONCLUSIONS
  Unopposed posterior teeth are more likely to be involved in RCP contacts or interferences than their matched controls. Many teeth were involved in multiple interferences, and there appears to be a number of interrelationships between these. Initial RCP contacts have associations with the extent of supraeruption of the unopposed teeth. The presence and position of the teeth distal to extraction sites was significant when modeling protrusive interferences. Protrusive interferences are more prevalent where the site of tooth loss was bounded. Mesial tipping of the teeth distal to extraction sites reduced this effect. Working side interferences were associated with tipping of teeth mesial to the site of tooth loss. No associations between patient or tooth factors were found for nonworking side interferences, and the only association found for these interferences were with protrusive interferences at the sites.
authors.affiliation: Restorative Dentistry, Leeds Dental Institute, Clarendon Way, Leeds, UK. H.L.Craddock@leeds.ac.uk
authors.forename: Helen L
authors.initials: HL
authors.lastname: Craddock
mesh_terms: D001641:Bicuspid; D016022:Case-Control Studies; D003735:Dental Casting Technique; D003769:Dental Occlusion, Traumatic / Q000145:classification / Q000209:etiology*; D005260:Female; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000150:complications* / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008310:Malocclusion / Q000145:classification / Q000209:etiology*; D016555:Matched-Pair Analysis; D008963:Molar; D016388:Tooth Loss / Q000150:complications* / Q000503:physiopathology; D014085:Tooth Migration / Q000150:complications* / Q000503:physiopathology; D014086:Tooth Mobility / Q000150:complications* / Q000503:physiopathology