title: Evaluation of post-surgical relapse after mandibular setback surgery with minimal orthodontic preparation.
abstract: BACKGROUND
  The aim of this study was to evaluate of the patterns of post-surgical relapse after mandibular setback surgery with minimal orthodontic preparation (MS-MO).
  
  
  METHODS
  The subjects consisted of 15 patients with minimal pre-surgical orthodontic preparation (1.37 ± 1.69 months). Lateral cephalograms were taken in pre-surgical (T0), post-surgical 1 month (T1) and immediately after debonding (T2) stages. To evaluate the surgical changes (T1-T0) and the relapse (T2-T1), the linear and angular measurements were analyzed using paired t-test. Pearson's correlation coefficients of the horizontal and vertical relapses of Pog and Me to other measurements were calculated. Pog or Me in T1 were displaced rotationally on Ar-Pog or Ar-Me lines in T2 to evaluate the remaining surgical relapse except the rotational relapse from total relapse.
  
  
  RESULTS
  The mandible relapsed anteriorly 3.53 mm (Pog) and 4.00 mm (Me) and superiorly 2.72 mm (Pog) and 2.44 mm (Me). FH to Ar-Pog and FH to Ar-Me decreased by about 2°. Pure surgical relapses at Pog and Me, except rotational relapses, were about 0.5 mm anteriorly and inferiorly 0.8 mm.
  
  
  CONCLUSIONS
  The vertical relapse might induce mandibular rotation with the horizontal relapse. For an accurate prediction after MS-MO, the rotational relapse might be considered.
authors: Department of Orthodontics, Seoul National University Bundang Hospital, Sungnam, South Korea.
authors: Nam-Ki
authors: NK
authors: Lee
authors: Young-Kyun
authors: YK
authors: Kim
authors: Pil-Young
authors: PY
authors: Yun
authors: Jong-Wan
authors: JW
authors: Kim
mesh_terms: D059925:Anatomic Landmarks / Q000473:pathology; D002508:Cephalometry / Q000379:methods; D002680:Chin / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000473:pathology / Q000601:surgery; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D008335:Mandibular Condyle / Q000473:pathology; D009971:Orthodontics, Corrective / Q000379:methods*; D056948:Orthognathic Surgical Procedures / Q000379:methods*; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D012008:Recurrence; D012399:Rotation; D014716:Vertical Dimension; D055815:Young Adult