title: Analysis of 3D soft tissue changes after 1- and 2-jaw orthognathic surgery in mandibular prognathism patients.
abstract: OBJECTIVE
  Orthognathic surgery has the objective of altering facial balance to achieve esthetic results in patients who have severe disharmony of the jaws. The purpose was to quantify the soft tissue changes after orthognathic surgery, as well as to assess the differences in 3D soft tissue changes in the middle and lower third of the face between the 1- and 2-jaw surgery groups, in mandibular prognathism patients.
  
  
  METHODS
  We assessed soft tissue changes of patients who have been diagnosed with mandibular prognathism and received either isolated mandibular surgery or bimaxillary surgery. The quantitative surface displacement was assessed by superimposing preoperative and postoperative volumetric images. An observer measured a surface-distance value that is shown as a contour line. Differences between the groups were determined by the Mann-Whitney U test. The Spearman correlation coefficient was used to evaluate a potential correlation between patients' surgical and cephalometric variables and soft tissue changes after orthognathic surgery in each group.
  
  
  RESULTS
  There were significant differences in the middle third of the face between the 1- and 2-jaw surgery groups. Soft tissues in the lower third of the face changed in both surgery groups, but not significantly. The correlation patterns were more evident in the lower third of the face.
  
  
  CONCLUSIONS
  The overall soft tissue changes of the midfacial area were more evident in the 2-jaw surgery group. In 2-jaw surgery, significant changes would be expected in the midfacial area, but caution should be exercised in patients who have a wide alar base.
authors.affiliation: Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Chuncheon, South Korea.
authors.forename: Bo-Ram
authors.initials: BR
authors.lastname: Kim
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Oh
authors.forename: Lucia H S
authors.initials: LH
authors.lastname: Cevidanes
authors.forename: Jeong-Eon
authors.initials: JE
authors.lastname: Park
authors.forename: Hyoung-Seob
authors.initials: HS
authors.lastname: Sim
authors.forename: Sung-Kyung
authors.initials: SK
authors.lastname: Seo
authors.forename: Mauricio
authors.initials: M
authors.lastname: Reyes
authors.forename: Yoon-Ji
authors.initials: YJ
authors.lastname: Kim
authors.forename: Yang-Ho
authors.initials: YH
authors.lastname: Park
mesh_terms: D002508:Cephalometry; D054893:Cone-Beam Computed Tomography; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008334:Mandible / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery*; D008445:Maxillofacial Development; D056948:Orthognathic Surgical Procedures / Q000379:methods; D019340:Osteotomy, Le Fort; D059229:Osteotomy, Sagittal Split Ramus; D011378:Prognathism / Q000601:surgery*; D018709:Statistics, Nonparametric; D055815:Young Adult