title: Social smile reproducibility using 3-D stereophotogrammetry and reverse engineering technology.
abstract: OBJECTIVE
  To assess the range of social smile reproducibility using 3-D stereophotogrammetry and reverse engineering technology.
  
  
  METHODS
  Social smile images of white adolescents (N  =  15, mean age  =  15.4 ±1.5 years; range  =  14-17 years) were obtained using 3dMDFlex (3dMD, Atlanta, Ga). Each participant was asked to produce 16 social smiles at 3-minute intervals. All images were obtained in natural head position. Alignment of images, segmentation of smile area, and 3-D deviation analysis were carried out using Geomagic Control software (3D Systems Inc, Cary, NC). A single image was taken as a reference, and the remaining 15 images were compared with the reference image to evaluate positive and negative deviations. The differences between the mean deviation limits of participants with the highest and the lowest deviations and the total mean deviations were evaluated using Bland-Altman Plots.
  
  
  RESULTS
  Minimum and maximum deviations of a single image from the reference image were 0.34 and 2.69 mm, respectively. Lowest deviation between two images was within 0.5 mm and 1.54 mm among all participants (mean, 0.96 ± 0.21 mm), and the highest deviation was between 0.41 mm and 2.69 mm (mean, 1.53 ± 0.46 mm). For a single patient, when all alignments were considered together, the mean deviation was between 0.32 ± 0.10 mm and 0.59 ± 0.24 mm. Mean deviation for one image was between 0.14 and 1.21 mm.
  
  
  CONCLUSIONS
  The range of reproducibility of the social smile presented individual variability, but this variation was not clinically significant or detectable under routine clinical observation.
authors.affiliation: a  Research Assistant, Department of Orthodontics, Dental Sciences Center, Gülhane Military Medical Academy, Ankara, Turkey.
authors.forename: Furkan
authors.initials: F
authors.lastname: Dindaroğlu
authors.affiliation: b  PhD Student, Department of Orthodontics, Dental Sciences Center, Gülhane Military Medical Academy, Ankara, Turkey.
authors.forename: Gökhan Serhat
authors.initials: GS
authors.lastname: Duran
authors.affiliation: c  Associate Professor, Department of Orthodontics, Dental Sciences Center, Gülhane Military Medical Academy, Ankara, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Görgülü
authors.affiliation: d  Associate Professor, Department of Orthodontics, School of Dentistry, Ege University, İzmir, Turkey.
authors.forename: Enver
authors.initials: E
authors.lastname: Yetkiner
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D010780:Photogrammetry; D015203:Reproducibility of Results; D012904:Smiling; D012984:Software
keywords: Reproducibility; Reverse engineering; Social smile