title: Postoperative relapse after mandibular setback surgery with perioperative counterclockwise rotation of the mandibular proximal segment.
abstract: OBJECTIVE
  This study aimed to evaluate whether the perioperative counterclockwise rotation (CCWR) of the proximal segment (PS) can reduce relapse after mandibular setback surgery.
  
  
  METHODS
  Patients who underwent less than 1° of bilateral perioperative rotation of the PS were assigned to group I (n = 15). Group II (n = 14) included patients who showed greater than 1° of perioperative CCWR bilaterally. To evaluate the PS rotation and the relapse, three-dimensional computed tomography (CT) and lateral cephalography scans were analyzed.
  
  
  RESULTS
  Even with significantly different perioperative CCWR of the PS (.07 ± .53° vs -3.47 ± 1.55°), the relapse was not significantly different between group I (1.96 ± 1.15 mm) and group II (1.81 ± .92 mm). However, postoperative CCWR of the PS was significantly greater in group I. The relapse was not influenced by the amount of setback.
  
  
  CONCLUSIONS
  A small degree of relapse is expected after mandibular setback surgery, even with perioperative CCWR of the PS.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, School of Dentistry, Dental Research Institute, BK 21 Plus, Seoul National University, Korea.
authors.forename: Jae Bong
authors.initials: JB
authors.lastname: Park
authors.affiliation: Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, School of Dentistry, Dental Research Institute, BK 21 Plus, Seoul National University, Korea.
authors.forename: Im Geon
authors.initials: IG
authors.lastname: Jin
authors.affiliation: Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, School of Dentistry, Dental Research Institute, BK 21 Plus, Seoul National University, Korea.
authors.forename: Jeong Joon
authors.initials: JJ
authors.lastname: Han
authors.affiliation: Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, School of Dentistry, Dental Research Institute, BK 21 Plus, Seoul National University, Korea. Electronic address: sjhwang@snu.ac.kr.
authors.forename: Soon Jung
authors.initials: SJ
authors.lastname: Hwang
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D059925:Anatomic Landmarks; D002508:Cephalometry; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery; D009971:Orthodontics, Corrective; D059229:Osteotomy, Sagittal Split Ramus; D011378:Prognathism / Q000000981:diagnostic imaging* / Q000601:surgery*; D012008:Recurrence; D012189:Retrospective Studies; D012399:Rotation; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome