title: [Occlusal plane orientation and postoperative anterior open bite relapse].
abstract: BACKGROUND
  Most published data on relapse in open bite maxillo-mandibular deformities give raw results but do not suggest any specific therapy. Indeed, their authors compare the various osteotomy techniques but without identifying risk factors for relapse (dysfunctional or architectural). We studied the predictive value of occlusal plane tilting, in the long-term relapse of open bite maxillo-mandibular deformity.
  
  
  METHODS
  Fifty patients were included between 1996 and 2007. For each patient, Delaire cephalometric analysis was performed on preoperative, immediate and late postoperative teleradiographs. Immediate real postoperative occlusal plane tilting was analyzed and compared with "ideal" theoretical occlusal plane tilting (calculated with Delaires' analysis). The patients were classified in two groups: one with slight discrepancy between these two planes (+/-3.75 degrees) and one with large discrepancies between these two planes (greater than 3.75 degrees or lesser than 3.75 degrees).
  
  
  RESULTS
  Postoperative relapse was seven times more frequent when the postoperative plane tilting was superior to +/-3.75 degrees in reference to the ideal plane.
  
  
  CONCLUSIONS
  Postoperative occlusal plane tilting is a predictive factor of postoperative open bite relapse.
authors.affiliation: Service de chirurgie maxillofaciale et stomatologie, CHU de la Timone, boulevard Jean-Moulin, 13385 Marseille, France. pierre.olivi@ap-hm.fr
authors.forename: P
authors.initials: P
authors.lastname: Olivi
authors.forename: F
authors.initials: F
authors.lastname: Cheynet
authors.forename: C
authors.initials: C
authors.lastname: Chossegros
authors.forename: J-L
authors.initials: JL
authors.lastname: Blanc
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000150:complications / Q000175:diagnosis; D008875:Middle Aged; D024343:Open Bite / Q000601:surgery*; D056948:Orthognathic Surgical Procedures; D019340:Osteotomy, Le Fort; D011237:Predictive Value of Tests; D012008:Recurrence; D012189:Retrospective Studies; D055815:Young Adult