title: Three-dimensional evaluation of changes in lip position from before to after orthodontic appliance removal.
abstract: BACKGROUND
  Our objectives were to develop a reproducible method of superimposing 3-dimensional images for measuring soft-tissue changes over time and to use this method to document changes in lip position after the removal of orthodontic appliances.
  
  
  METHODS
  Three-dimensional photographs of 50 subjects were made in repose and maximum intercuspation before and after orthodontic appliance removal with a stereo camera. For reliability assessment, 2 photographs were repeated for 15 patients. The images were registered on stable areas, and surface-to-surface measurements were made for defined landmarks.
  
  
  RESULTS
  Mean changes were below the level of clinical significance (set at 1.5 mm). However, 51% and 18% of the subjects experienced changes greater than 1.5 mm at the commissures and lower lips, respectively.
  
  
  CONCLUSIONS
  The use of serial 3-dimensional photographs is a reliable method of documenting soft-tissue changes. Soft-tissue changes after appliance removal are not clinically significant; however, there is great individual variability.
authors.affiliation: Department of Orthodontics, University of North Carolina, Chapel Hil, USA. lindseyeidsondds@gmail.com
authors.forename: Lindsey
authors.initials: L
authors.lastname: Eidson
authors.forename: Lucia H S
authors.initials: LH
authors.lastname: Cevidanes
authors.forename: Leonardo Koerich
authors.initials: LK
authors.lastname: de Paula
authors.forename: H Garland
authors.initials: HG
authors.lastname: Hershey
authors.forename: Gregory
authors.initials: G
authors.lastname: Welch
authors.forename: P Emile
authors.initials: PE
authors.lastname: Rossouw
mesh_terms: D017005:Dental Debonding; D006801:Humans; D021621:Imaging, Three-Dimensional; D008046:Lip / Q000033:anatomy & histology*; D009967:Orthodontic Appliances / Q000009:adverse effects*; D023861:Photography, Dental / Q000379:methods*; D015203:Reproducibility of Results; D013382:Subtraction Technique