title: LeFort I maxillary advancement: 3-year stability and risk factors for relapse.
abstract: BACKGROUND
  The objectives of this retrospective cephalometric study were to assess the amount, direction, and timing of postoperative changes after LeFort I maxillary advancement, and to identify risk factors for skeletal relapse.
  
  
  METHODS
  The material was selected from the files at the Department of Orthodontics, University of Oslo, and comprised 43 patients who underwent 1-piece LeFort I advancement as the only surgical procedure from 1990 to 1998. All patients were followed for 3 years by using a strict data collection protocol. Lateral cephalograms were obtained before surgery and at 5 times after surgery.
  
  
  RESULTS
  A mean relapse of 18% of the surgical advancement occurred. In 14% of the patients, clinically significant skeletal relapse (> or = 2 mm) was observed. Most (89%) postoperative change occurred during the first 6 months after surgery. Skeletal relapse increased significantly with degree of surgical advancement (P = .001) and degree of inferior repositioning of the anterior maxilla (P = .004) (linear regression analysis). At the end of follow-up, overjet and overbite were within clinically acceptable ranges for all patients.
  
  
  CONCLUSIONS
  Maxillary advancement with a 1-piece LeFort I osteotomy is a relatively stable procedure. Identified risk factors for horizontal relapse were degree of surgical advancement and degree of inferior repositioning of anterior maxilla.
authors.affiliation: Department of Public and Child Dental Health, Trinity College, Dublin, Ireland.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Dowling
authors.forename: Lisen
authors.initials: L
authors.lastname: Espeland
authors.forename: Leiv
authors.initials: L
authors.lastname: Sandvik
authors.forename: Karim A
authors.initials: KA
authors.lastname: Mobarak
authors.forename: Hans Erik
authors.initials: HE
authors.lastname: Hogevold
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery*; D008437:Maxilla / Q000502:physiology / Q000601:surgery; D008875:Middle Aged; D019340:Osteotomy, Le Fort; D017063:Outcome Assessment, Health Care / Q000379:methods; D011184:Postoperative Period; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric