title: Stability of mandibular setback surgery with and without presurgical orthodontics.
abstract: OBJECTIVE
  The purpose of this study was to compare stability after mandibular setback surgery in patients with skeletal Class III malocclusion with and without presurgical orthodontics.
  
  
  METHODS
  This retrospective cohort study included consecutive patients with skeletal Class III malocclusion who underwent only mandibular surgery. Patients treated with the surgery-first approach without presurgical orthodontics (SF group) were compared with a control group (conventional surgery with presurgical orthodontics; CS group) using lateral cephalograms taken preoperatively, immediately postoperatively, and at the time of debonding. Predictor variables (group and timing), outcome variables (cephalometric measurements over time), and other variables, such as baseline characteristics, were evaluated to determine the difference in stability of mandibular positions such as the B point.
  
  
  RESULTS
  Sixty-one patients were enrolled in this study (CS group, n = 38; SF group, n = 23). Baseline demographic variables were similar in the 2 groups except for orthodontic treatment period. The mean setback of the mandible at the B point was similar (CS group, 8.7 mm; SF group, 9.1 mm; difference, P > .05), but the horizontal relapse in the SF group (2.4 mm) was significantly greater than in the CS group (1.6 mm; P < .05). Patients with a horizontal relapse greater than 3 mm comprised 39.1% of the SF group compared with 15.8% of the CS group (P < .05).
  
  
  CONCLUSIONS
  Mandibular sagittal split ramus osteotomy without presurgical orthodontic treatment was less stable than conventional orthognathic surgery for mandibular prognathism. Before performing a surgery-first approach, skeletal stability needs to be considered.
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Chin-Soo
authors.initials: CS
authors.lastname: Kim
authors.affiliation: Resident, Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Sang-Chang
authors.initials: SC
authors.lastname: Lee
authors.affiliation: Professor, Center for Orthognathic Surgery, Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Hee-Moon
authors.initials: HM
authors.lastname: Kyung
authors.affiliation: Professor, Center for Orthognathic Surgery, Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Hyo-Sang
authors.initials: HS
authors.lastname: Park
authors.affiliation: Professor, Center for Orthognathic Surgery, Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyungpook National University, Daegu, Korea. Electronic address: taegeonkwon@gmail.com.
authors.forename: Tae-Geon
authors.initials: TG
authors.lastname: Kwon
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007180:Incisor / Q000473:pathology; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery* / Q000628:therapy; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D008437:Maxilla / Q000473:pathology; D008963:Molar / Q000473:pathology; D016910:Orthodontic Brackets; D056948:Orthognathic Surgical Procedures / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D011378:Prognathism / Q000601:surgery / Q000628:therapy; D012008:Recurrence; D012189:Retrospective Studies; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome; D014716:Vertical Dimension; D055815:Young Adult