title: Development of virtual simulation platform for investigation of the radiographic features of periapical bone lesion.
abstract: BACKGROUND
  The periapical radiograph is used as an important tool in the assessment of periapical bone lesions in endodontic therapy. The purpose of this study was to develop a virtual simulation platform for radiographic research of periapical bone lesions based on a digitally reconstructed radiograph and to investigate the radiographic features of different simulated periapical bone lesions.
  
  
  METHODS
  A cadaver mandible was scanned by microcomputed tomography. The application framework for the creation of a digitally reconstructed radiograph with virtual periapical lesions was constructed. Subsequently, different size and shape periapical lesions were created virtually in an incisor, a premolar, and a molar, and the digitally reconstructed radiographs were produced.
  
  
  RESULTS
  The detection of periapical lesions based on digitally reconstructed radiographs was depended on lesion size, position, shape, and tooth position. Virtual periapical lesions could not be visualized with lesions smaller than 1 mm in the incisor, 2 mm in the premolar, and 3 mm in the molar, and these virtual lesions were confined within the cancellous bone. A 4-mm lesion in the molar was still not visualized even if it encroached on the cortical bone. If the lesions encroached on the junctional trabeculae and cortical bone or the lesion was created with the maximal buccal-lingual dimension in ellipsoid shape and confined within the cancellous bone giving it an abnormal shape, it could be seen, except for the "thinnest" 1-mm lesion in incisor region.
  
  
  CONCLUSIONS
  The virtual simulation platform described here provides a reproducible assessment of periapical lesions and aids in a better understanding of the characteristics of periapical lesions.
authors.affiliation: State Key Laboratory of Oral Diseases, West China College and Hospital of Stomatology, Sichuan University, Chengdu, China 610041.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.forename: Markus
authors.initials: M
authors.lastname: Haapasalo
authors.forename: Ya
authors.initials: Y
authors.lastname: Shen
authors.forename: Hongkun
authors.initials: H
authors.lastname: Wu
authors.forename: Huiyong
authors.initials: H
authors.lastname: Jiang
authors.forename: Xuedong
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D019412:Anatomy, Cross-Sectional; D001641:Bicuspid / Q000000981:diagnostic imaging; D002102:Cadaver; D003198:Computer Simulation; D017076:Computer-Aided Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007180:Incisor / Q000000981:diagnostic imaging; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging; D008336:Mandibular Diseases / Q000000981:diagnostic imaging; D008954:Models, Biological; D008963:Molar / Q000000981:diagnostic imaging; D010483:Periapical Diseases / Q000000981:diagnostic imaging*; D016300:Radiography, Bitewing; D012984:Software; D014092:Tooth Root / Q000000981:diagnostic imaging; D014584:User-Computer Interface; D055114:X-Ray Microtomography