title: Correlation between skeletal and dental changes after mandibular setback surgery-first orthodontic treatment: Cone-beam computed tomography-generated half-cephalograms.
abstract: OBJECTIVE
  To investigate skeletal and dental changes after application of a mandibular setback surgery-first orthodontic treatment approach in cases of skeletal Class III malocclusion.
  
  
  METHODS
  A retrospective study of 34 patients (23 men, 11 women; mean age, 26.2 ± 6.6 years) with skeletal Class III deformities, who underwent surgery-first orthodontic treatment, was conducted. Skeletal landmarks in the maxilla and mandible at three time points, pre-treatment (T0), immediate-postoperative (T1), and post-treatment (T2), were analyzed using cone-beam computed tomography (CBCT)-generated half-cephalograms.
  
  
  RESULTS
  The significant T0 to T1 mandibular changes occurred -9.24 ± 3.97 mm horizontally. From T1 to T2, the mandible tended to move forward 1.22 ± 2.02 mm, while the condylar position (Cd to Po-perpendicular plane) shifted backward, and the coronoid process (Cp to FH plane) moved vertically. Between T1 and T2, the vertical dimension changed significantly (p < 0.05). Changes in the vertical dimension were significantly correlated to T1 to T2 changes in the Cd to Po-perpendicular plane (r = -0.671, p = 0.034), and in the Cp to FH plane (r = 0.733, p = 0.016), as well as to T0 to T1 changes in the Cp to Po-perpendicular plane (r = 0.758, p = 0.011).
  
  
  CONCLUSIONS
  Greater alterations in the vertical dimension caused larger post-treatment (T2) stage skeletal changes. Studying the mandibular position in relation to the post-surgical vertical dimension emphasized the integral importance of vertical dimension control and proximal segment management to the success of surgery-first orthodontic treatment.
authors: Private Practice, Busan, Korea.
authors: Chang-Hoon
authors: CH
authors: Rhee
authors: Department of Orthodontics, Biomedical Research Institute, Pusan National University Hospital, Busan, Korea.
authors: Youn-Kyung
authors: YK
authors: Choi
authors: Department of Orthodontics, Biomedical Research Institute, Pusan National University Hospital, Busan, Korea. ; Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea.
authors: Yong-Il
authors: YI
authors: Kim
authors: Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea.
authors: Seong-Sik
authors: SS
authors: Kim
authors: Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea.
authors: Soo-Byung
authors: SB
authors: Park
authors: Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea.
authors: Woo-Sung
authors: WS
authors: Son
keywords: Class III orthognathic surgery; Computed tomography; Three-dimensional cephalometrics