title: Measurement of three-dimensional perioral soft tissue changes in dentoalveolar protrusion patients after orthodontic treatment using a structured light scanner.
abstract: OBJECTIVE
  To evaluate the three-dimensional (3D) perioral soft tissue changes after orthodontic treatment in patients with dentoalveolar protrusion using structured light-based scanners.
  
  
  METHODS
  Forty-four Korean adults (19 men and 25 women, 21.4 ± 3.4 years) with dentoalveolar protrusion treated by extraction of all four first premolars and then en masse retraction with maximum anchorage were evaluated. Lateral cephalograms and 3D facial scans were obtained before treatment (T1) and immediately after debonding (T2). Superimposition was performed, and 27 perioral landmarks were identified. The 3D changes in the landmarks and ratio of movement of the soft tissue relative to the horizontal incisal tip were evaluated. A paired t-test and one-way analysis of variance were performed.
  
  
  RESULTS
  The upper incisors were retracted 5.76 mm and the lower incisors were retracted 4.62 mm (P < .001). The upper lip moved inferoposteriorly, and the lower lip moved superoposteriorly. In the lower lip, upward movement was greater than backward movement (P < .001). The most prominent changes appeared at the greatest bulge area. The relative ratios were 42%-53% in the upper lip area and 22%-82% in the lower lip area. The lip corners moved superoposteriorly (P < .001). Subnasale moved downward (P < .05) and posteriorly (P < .001), while the landmarks under the nostrils moved upward and posteriorly (P < .001).
  
  
  CONCLUSIONS
  Facial scans from white structured light scanners efficiently evaluated 3D perioral soft tissue in dentoalveolar protrusion patients. Backward movement and significant vertical movement of the lip were observed. The nasal and lip angle areas showed considerable changes.
authors.affiliation: a  Assistant Professor, Department of Orthodontics, Oral Biology Research Institute, Kyung Hee University School of Dentistry, Seoul, Korea.
authors.forename: Hyo-Won
authors.initials: HW
authors.lastname: Ahn
authors.forename: Ye-Jin
authors.initials: YJ
authors.lastname: Chang
authors.forename: Kyung-A
authors.initials: KA
authors.lastname: Kim
authors.forename: Sang-Hwan
authors.initials: SH
authors.lastname: Joo
authors.forename: Young-Guk
authors.initials: YG
authors.lastname: Park
authors.forename: Ki-Ho
authors.initials: KH
authors.lastname: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D059925:Anatomic Landmarks / Q000033:anatomy & histology; D001641:Bicuspid / Q000601:surgery; D002508:Cephalometry / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007180:Incisor / Q000033:anatomy & histology; D008046:Lip / Q000033:anatomy & histology; D008297:Male; D008311:Malocclusion, Angle Class I / Q000628:therapy*; D009055:Mouth / Q000033:anatomy & histology*; D055171:Nasal Cartilages / Q000033:anatomy & histology; D009666:Nose / Q000033:anatomy & histology; D061848:Optical Imaging / Q000379:methods; D014081:Tooth Extraction / Q000379:methods; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult
keywords: 3D analysis; Dentoalveolar protrusion; Perioral soft tissue; Structured light–based scanners