title: Integration of digital dental casts in 3-dimensional facial photographs.
abstract: BACKGROUND
  Since 1915, various researchers have tried to make a 3-dimensional (3D) model of the complete face, with the dentition in the anatomically correct position. This was a difficult and time-consuming process. With the introduction of 3D digital imaging of the face and dental casts, researchers have regained interest in this topic. The purpose of this technical report is to present a feasibility study of the integration of a digital dental cast into a 3D facial picture.
  
  
  METHODS
  For the integration, 3 digital data sets were constructed: a digital dental cast, a digital 3D photograph of the patient with the teeth visible, and a digital 3D photograph of the patient with the teeth in occlusion. By using a special iterated closest point algorithm, these 3 data sets were matched to place them in the correct anatomical position.
  
  
  RESULTS
  After matching the 3 data sets, we obtained a 3D digital model with the dental cast visible through the transparent picture of the patient's face. When the distance between the matched data sets was calculated, an average distance of 0.35 mm (SD, 0.32 mm) was shown. This means that matching the data sets is acceptable.
  
  
  CONCLUSIONS
  It seems technically possible to make a data set of a patient's face with the dentition positioned into this 3D picture. Future research needs to establish the value of this 3D fused data set of the face and the dentition in orthodontic diagnosis and treatment planning.
authors.affiliation: Department of Orthodontics and Oral Biology, 3D Facial Imaging Research Group, Nijmegen and Bruges, and Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Frits A
authors.initials: FA
authors.lastname: Rangel
authors.forename: Thomas J J
authors.initials: TJ
authors.lastname: Maal
authors.forename: Stefaan J
authors.initials: SJ
authors.lastname: Bergé
authors.forename: Olivier J C
authors.initials: OJ
authors.lastname: van Vlijmen
authors.forename: Joanneke M
authors.initials: JM
authors.lastname: Plooij
authors.forename: Filip
authors.initials: F
authors.lastname: Schutyser
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Kuijpers-Jagtman
mesh_terms: D000465:Algorithms; D003761:Dental Impression Technique; D005145:Face / Q000033:anatomy & histology*; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007574:Jaw Relation Record; D003765:Models, Dental; D010780:Photogrammetry; D010781:Photography / Q000379:methods*; D012984:Software; D014057:Tomography, X-Ray Computed