title: Bilateral sagittal split osteotomy for correction of mandibular prognathism: long-term results.
abstract: OBJECTIVE
  To identify the long-term maxillomandibular changes after surgical correction of mandibular prognathism using bilateral sagittal split osteotomy (BSSO).
  
  
  METHODS
  Twenty patients who underwent BSSO to setback the mandible and had cephalometric radiographs taken preoperatively and postoperatively at 6 weeks, 1 year, and long-term follow-up (mean, 28 months). The cephalograms were traced and measured to determine the operative and postoperative changes. Correlation analyses were performed to see the relationship between the magnitude of setback and the amount of long-term postsurgical change at B point and pogonion.
  
  
  RESULTS
  The mean surgical setback was 8.2 mm at B point and 8.8 mm at pogonion. The mean long-term horizontal relapse was 2.3 mm (28.0%) at B point and 3.0 mm (34.1%) at pogonion. Out of 20 patients, 12 (60.0%) relapsed horizontally greater than 2 mm at B point and 13 (65.0%) at pogonion. The mean vertical surgical changes showed downward displacement of B point (2.3 mm) and pogonion (2.0 mm). The mean long-term vertical relapse was 1.6 mm (69.6%) at B point and 1.7 mm (85.0%) at pogonion.
  
  
  CONCLUSIONS
  There was no correlation between the magnitude of setback and the amount of relapse at B point and pogonion. However, there was significant correlation between the magnitude of vertical, downward surgical displacement and the amount of vertical relapse at B point and pogonion. The majority of the maxillofacial changes occurred within 1 year postoperatively.
authors.affiliation: Cleft Palate Team, Our Lady of Peace Hospital, Paranaque, Philippines.
authors.forename: Glenda H
authors.initials: GH
authors.lastname: de Villa
authors.forename: Chiung-Shing
authors.initials: CS
authors.lastname: Huang
authors.forename: Philip K T
authors.initials: PK
authors.lastname: Chen
authors.forename: Yu-Ray
authors.initials: YR
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019248:Jaw Fixation Techniques; D007574:Jaw Relation Record; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D019647:Oral Surgical Procedures / Q000379:methods*; D010027:Osteotomy / Q000379:methods*; D011378:Prognathism / Q000601:surgery*; D011859:Radiography; D012008:Recurrence; D016896:Treatment Outcome; D014716:Vertical Dimension