title: Intraoral Vertical Ramus Osteotomy Results in Good Long-Term Mandibular Stability in Patients With Mandibular Prognathism and Anterior Open Bite.
abstract: OBJECTIVE
  Few studies have evaluated the outcomes of intraoral vertical ramus osteotomy (IVRO) for the correction of skeletal Class III malocclusion with an anterior open bite and the potential for postoperative relapse. Therefore, this study evaluated the stability of outcomes of IVRO for mandibular prognathism with and without an anterior open bite.
  
  
  METHODS
  This retrospective cohort study included consecutive patients with skeletal Class III malocclusion with (AOB group) and without (NAOB group) an anterior open bite who underwent IVRO at Yonsei Dental Hospital (Seoul, Korea). Lateral cephalograms were analyzed for predictor (open bite, yes or no) and outcome (horizontal and vertical relapse in the mandible) variables before and 7 days, 1 year, and 2 years after surgery. Other variables included the patients' demographic characteristics. Data were analyzed using independent t tests, repeated measures analysis of variance, Pearson correlation coefficients, and multiple linear regression analysis.
  
  
  RESULTS
  The 2 groups (n = 15 each) were matched for baseline demographic characteristics. During the 2-year postoperative period, anterior and superior mandibular movements were observed in the NAOB group, whereas posterior and superior movements were observed in the AOB group. However, there were no meaningful intergroup differences in horizontal and vertical relapses of the mandible at all time points, although the amount of postoperative inferior relapse increased with a decrease in the amount of initial overbite.
  
  
  CONCLUSIONS
  IVRO for the correction of skeletal Class III malocclusion resulted in good postoperative stability over time, regardless of the presence of a preoperative open bite, although the amount of postoperative inferior relapse showed a weak negative correlation with the initial overbite. Thus, IVRO can be a clinically acceptable treatment for skeletal Class III malocclusion with an anterior open bite.
authors.affiliation: Fellow, Department of Orthodontics, The institute of Cranio-Facial Deformity, College of Dentistry, Yonsei University, Seoul, Korea. Electronic address: hwang@yuhs.ac.
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Associate Professor, Department of Orthodontics, The institute of Cranio-Facial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Jung-Yul
authors.initials: JY
authors.lastname: Cha
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Hyung-Sik
authors.initials: HS
authors.lastname: Park
authors.affiliation: Professor, Department of Orthodontics, The institute of Cranio-Facial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Chung-Ju
authors.initials: CJ
authors.lastname: Hwang
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019248:Jaw Fixation Techniques; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery; D008334:Mandible / Q000601:surgery*; D063168:Mandibular Osteotomy / Q000379:methods*; D008437:Maxilla / Q000601:surgery; D024343:Open Bite / Q000601:surgery*; D019340:Osteotomy, Le Fort / Q000379:methods; D026741:Physical Therapy Modalities; D011378:Prognathism / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome; D014716:Vertical Dimension; D055815:Young Adult