title: [Quantitative evaluation of three-dimensional reconstruction accuracy of edentulous models in centric relation].
abstract: OBJECTIVE
  To reconstruct the centric relation of upper and lower edentulous dental models with two methods, to compare the reconstruction accuracy of the vertical and horizontal distance, and to provide some references to computer aided design and computer aided manufacture for complete denture.
  
  
  METHODS
  Dental models and rims made from five edentulous patients in clinical were obtained.Each model was stocked with 10 identical size positioning cylinders (20 cylinders on each pair models) on 5 side-surfaces of basement. Twelve center point pairs were paired between upper and lower models from 20 cylinder bottoms. The vertical and horizontal distances of 12 center point pairs were regarded as the evaluation items. Firstly, upper and lower models and rims were scanned separately. Then, models and rims (fixed in centric relation respectively with positioning articulator and rubber banding) were scanned.In software, all the data were registered to reconstruct centric relation based on common region. Digital models were measured with software tools, and real models were measured with a contact measurement arm. The differences of the homologous items between two methods were analyzed with paired-t test.
  
  
  RESULTS
  The vertical distance errors for dental articulator positioning method was (0.356 ± 0.200) mm and that of the rubber band method was (0.382 ± 0.299) mm, and paired-t test between the two methods showed no significant differences (P > 0.05). The horizontal errors were (0.010 ± 0.411) mm and (0.104 ± 0.476) mm, and paired-t test showed significant differences (P < 0.05).
  
  
  CONCLUSIONS
  Comparing with rubber band method, dental articulator positioning can significantly increases three-dimensional reconstruction accuracy of edentulous jaw gypsum models' horizontal relation.
authors.affiliation: Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing 100081, China.
authors.forename: Yuchun
authors.initials: Y
authors.lastname: Sun
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Email: kqlpj@bjmu.edu.cn.
authors.forename: Peijun
authors.initials: P
authors.lastname: Lyu
mesh_terms: D016302:Centric Relation; D017076:Computer-Aided Design; D003725:Dental Articulators; D003824:Denture, Complete; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007575:Jaw, Edentulous; D003765:Models, Dental; D009066:Mouth, Edentulous; D012984:Software; D014057:Tomography, X-Ray Computed