title: Tooth-size discrepancy: a comparison between manual and digital methods.
abstract: BACKGROUND
  Technological advances in Dentistry have emerged primarily in the area of diagnostic tools. One example is the 3D scanner, which can transform plaster models into three-dimensional digital models.
  
  
  OBJECTIVE
  This study aimed to assess the reliability of tooth size-arch length discrepancy analysis measurements performed on three-dimensional digital models, and compare these measurements with those obtained from plaster models.
  
  
  METHODS
  To this end, plaster models of lower dental arches and their corresponding three-dimensional digital models acquired with a 3Shape R700T scanner were used. All of them had lower permanent dentition. Four different tooth size-arch length discrepancy calculations were performed on each model, two of which by manual methods using calipers and brass wire, and two by digital methods using linear measurements and parabolas.
  
  
  RESULTS
  Data were statistically assessed using Friedman test and no statistically significant differences were found between the two methods (P > 0.05), except for values found by the linear digital method which revealed a slight, non-significant statistical difference.
  
  
  CONCLUSIONS
  Based on the results, it is reasonable to assert that any of these resources used by orthodontists to clinically assess tooth size-arch length discrepancy can be considered reliable.
authors.forename: Gabriele Dória Cabral
authors.initials: GD
authors.lastname: Correia
authors.forename: Fernando Antonio Lima
authors.initials: FA
authors.lastname: Habib
authors.forename: Carlos Jorge
authors.initials: CJ
authors.lastname: Vogel
mesh_terms: D059925:Anatomic Landmarks / Q000033:anatomy & histology; D001641:Bicuspid / Q000033:anatomy & histology; D003481:Cuspid / Q000033:anatomy & histology; D003724:Dental Arch / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007180:Incisor / Q000033:anatomy & histology; D003765:Models, Dental; D008963:Molar / Q000033:anatomy & histology; D009811:Odontometry / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D014070:Tooth / Q000033:anatomy & histology*
keywords: Computer-assisted diagnosis; Dental models; Three-dimensional imaging