title: Three-year follow-up of bimaxillary surgery to correct skeletal Class III malocclusion: stability and risk factors for relapse.
abstract: BACKGROUND
  The purpose of this study was to evaluate long-term skeletal and occlusal stability after bimaxillary surgery to correct skeletal Class III malocclusion.
  
  
  METHODS
  The sample comprised 81 consecutively treated patients. All subjects had received a combined 1-piece LeFort I and bilateral sagittal split ostotomies with rigid fixation between 1990 and 2003 and were followed for 3 years. Lateral cephalograms were obtained before surgery and at 5 occasions after surgery.
  
  
  RESULTS
  The mean setback was 6.9 mm in the mandible, and the maxilla was moved forward 3.7 mm. In most patients, the posterior maxilla was impacted. Relapse of maxillary advancement was insignificant (0.1 mm), whereas relapse at B-point was on average 1.7 mm (P <0.010). After 3 years, mean overjet and overbite amounts were 2.0 and 1.9 mm, respectively. Skeletal relapse of the mandible increased significantly with the surgical setback (P <0.001) and the change in the vertical position of the posterior maxilla (P = 0.010) (multivariate regression analysis).
  
  
  CONCLUSIONS
  Bimaxillary surgery resulted in good occlusal stability. Maxillary advancement was stable, whereas relapse of the mandibular setback varied. Risk factors for horizontal relapse of the mandible were large setback and inferior repositioning of the posterior maxilla.
authors.affiliation: Department of Orthodontics, Riga Stradins University, Riga, Latvia.
authors.forename: Gundega
authors.initials: G
authors.lastname: Jakobsone
authors.forename: Arild
authors.initials: A
authors.lastname: Stenvik
authors.forename: Leiv
authors.initials: L
authors.lastname: Sandvik
authors.forename: Lisen
authors.initials: L
authors.lastname: Espeland
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001863:Bone Screws; D002508:Cephalometry / Q000379:methods; D003766:Dental Occlusion; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019248:Jaw Fixation Techniques; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery*; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D008437:Maxilla / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D009295:Nasal Bone / Q000473:pathology; D009971:Orthodontics, Corrective / Q000295:instrumentation; D010027:Osteotomy / Q000379:methods; D019340:Osteotomy, Le Fort / Q000379:methods; D012008:Recurrence; D012307:Risk Factors; D012658:Sella Turcica / Q000473:pathology; D012737:Sex Factors; D016896:Treatment Outcome; D014716:Vertical Dimension; D055815:Young Adult