title: Accuracy of computerized automatic identification of cephalometric landmarks by a designed software.
abstract: OBJECTIVE
  The purpose of this study was to design software for localization of cephalometric landmarks and to evaluate its accuracy in finding landmarks.
  
  
  METHODS
  40 digital cephalometric radiographs were randomly selected. 16 landmarks which were important in most cephalometric analyses were chosen to be identified. Three expert orthodontists manually identified landmarks twice. The mean of two measurements of each landmark was defined as the baseline landmark. The computer was then able to compare the automatic system's estimate of a landmark with the baseline landmark. The software was designed using Delphi and Matlab programming languages. The techniques were template matching, edge enhancement and some accessory techniques.
  
  
  RESULTS
  The total mean error between manually identified and automatically identified landmarks was 2.59 mm. 12.5% of landmarks had mean errors less than 1 mm. 43.75% of landmarks had mean errors less than 2 mm. The mean errors of all landmarks except the anterior nasal spine were less than 4 mm.
  
  
  CONCLUSIONS
  This software had significant accuracy for localization of cephalometric landmarks and could be used in future applications. It seems that the accuracy obtained with the software which was developed in this study is better than previous automated systems that have used model-based and knowledge-based approaches.
authors.affiliation: Shiraz Biomaterial [corrected] Research Center, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. [corrected].
authors.forename: Sh
authors.initials: Sh
authors.lastname: Shahidi
authors.forename: S
authors.initials: S
authors.lastname: Shahidi
authors.forename: M
authors.initials: M
authors.lastname: Oshagh
authors.forename: F
authors.initials: F
authors.lastname: Gozin
authors.forename: P
authors.initials: P
authors.lastname: Salehi
authors.forename: S M
authors.initials: SM
authors.lastname: Danaei
mesh_terms: D000465:Algorithms; D059925:Anatomic Landmarks; D002508:Cephalometry; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D011381:Programming Languages; D011856:Radiographic Image Enhancement; D012985:Software Design