title: The assessment of the stability in mandibular setback surgery related to spatial factors under rotational control of the proximal segment.
abstract: OBJECTIVE
  To evaluate the surgical relapse of mandibular setback, related to the magnitude of setback and LeFort I osteotomy under rotational control of the proximal segment.
  
  
  METHODS
  Data from 78 patients who had undergone sagittal split ramus osteotomy for mandibular prognathism were reviewed. The stability of the proximal segment was retrospectively confirmed. Serial cephalograms were used to assess relapse over 1 year. The association between relapse and LeFort I osteotomy as well as the magnitude of setback was assessed.
  
  
  RESULTS
  Minimal counterclockwise rotation was noted postoperatively, but the proximal segment remained stable for 1 year. Notable forward relapse was shown in the setback of more than 7 mm (P < .01) with resumption of function after 6 weeks, but it was not related with LeFort I osteotomy.
  
  
  CONCLUSIONS
  Relapse was related to the amount of setback and occurred on resumption of function despite rotational control of the proximal segment.
authors.affiliation: Clinical Assistant Professor, Department of Oral and Maxillofacial Surgery, Seoul Asan Medical Center, Seoul, South Korea.
authors.forename: Jee Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Biostatistician, Department of Clinical Epidemiology and Biostatistics, Seoul Asan Medical Center, Seoul, South Korea.
authors.forename: Seon Ok
authors.initials: SO
authors.lastname: Kim
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, Seoul Asan Medical Center, Seoul, South Korea. Electronic address: amcomsjjh@gmail.com.
authors.forename: Ju Hong
authors.initials: JH
authors.lastname: Jeon
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D005260:Female; D006801:Humans; D019248:Jaw Fixation Techniques; D008297:Male; D019340:Osteotomy, Le Fort; D059229:Osteotomy, Sagittal Split Ramus; D011378:Prognathism / Q000601:surgery*; D012008:Recurrence; D012086:Reoperation; D012399:Rotation