title: Three-dimensional analysis of soft tissue changes in full-face view after surgical correction of skeletal class III malocclusion.
abstract: OBJECTIVE
  The objective of this study was to evaluate changes in soft tissue in full-face view because of surgical correction of skeletal Class III malocclusion, using 3-dimensional (3D) laser scanning.
  
  
  METHODS
  Twenty-seven subjects with skeletal Class III malocclusion [11 males; mean age (SD), 24.0 (5.7) years] underwent bilateral sagittal split ramus osteotomy for mandibular setback combined with Lefort I osteotomy with/without maxillary advancement. Twelve patients (group 1) had mandibular setback surgery, and the other 15 (group 2) had combination surgery. Lateral cephalograms and 3D facial scan images were assessed preoperatively and postoperatively. The facial widths upon superimposition of 3D facial images were measured in the same coordinates using a Rapidform 2006 system. Paired and independent t tests were done for statistical analysis.
  
  
  RESULTS
  The midface soft tissue broadened significantly above the cheilion plane postoperatively (P < 0.05). A larger change was observed nearer to subnasale plane, and a similar trend was seen among the horizontal planes in 1- or 2-jaw surgery groups. The widths from the exocanthion plane to the subnasale plane increased more in group 2 [mean (SD), 4.45 (2.45) mm, 8.71 (2.92) mm, and 7.62 (3.13) mm] than those in group 1 [mean (SD), 1.26 (0.97) mm, 1.84 (1.06) mm, and 1.35 (0.65) mm], and this difference was significant (P < 0.05). There was a decrease below the cheilion plane with mandibular setback between groups, but this difference was not significant.
  
  
  CONCLUSIONS
  The measurement method used here for the shape outline of the lateral parts of the face could provide quantitative data for the clinical evaluation and objective analysis of the human face in full-face view. The midface soft tissue in subjects with skeletal Class III malocclusion exhibited a greater increase in width after bimaxillary surgery procedures than mandibular setback-only surgery.
authors.affiliation: Center of Craniofacial Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, PR China.
authors.forename: Lingjun
authors.initials: L
authors.lastname: Yuan
authors.forename: Guofang
authors.initials: G
authors.lastname: Shen
authors.forename: Yong
authors.initials: Y
authors.lastname: Wu
authors.forename: Lingyong
authors.initials: L
authors.lastname: Jiang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yang
authors.forename: Jiaqiang
authors.initials: J
authors.lastname: Liu
authors.forename: Lixia
authors.initials: L
authors.lastname: Mao
authors.forename: Bing
authors.initials: B
authors.lastname: Fang
mesh_terms: D000293:Adolescent; D000328:Adult; D059925:Anatomic Landmarks / Q000033:anatomy & histology; D002508:Cephalometry / Q000379:methods*; D005143:Eyelids / Q000033:anatomy & histology; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007834:Lasers; D008046:Lip / Q000033:anatomy & histology; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery*; D008334:Mandible / Q000033:anatomy & histology / Q000601:surgery; D008437:Maxilla / Q000033:anatomy & histology / Q000601:surgery; D009666:Nose / Q000033:anatomy & histology; D019340:Osteotomy, Le Fort / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods; D055815:Young Adult