title: Evaluation of the quantitative accuracy of 3D reconstruction of edentulous jaw models with jaw relation based on reference point system alignment.
abstract: OBJECTIVE
  To apply contact measurement and reference point system (RPS) alignment techniques to establish a method for 3D reconstruction of the edentulous jaw models with centric relation and to quantitatively evaluate its accuracy.
  
  
  METHODS
  Upper and lower edentulous jaw models were clinically prepared, 10 pairs of resin cylinders with same size were adhered to axial surfaces of upper and lower models. The occlusal bases and the upper and lower jaw models were installed in the centric relation position. Faro Edge 1.8m was used to directly obtain center points of the base surface of the cylinders (contact method). Activity 880 dental scanner was used to obtain 3D data of the cylinders and the center points were fitted (fitting method). 3 pairs of center points were used to align the virtual model to centric relation. An observation coordinate system was interactively established. The straight-line distances in the X (horizontal left/right), Y (horizontal anterior/posterior), and Z (vertical) between the remaining 7 pairs of center points derived from contact method and fitting method were measured respectively and analyzed using a paired t-test.
  
  
  RESULTS
  The differences of the straight-line distances of the remaining 7 pairs of center points between the two methods were X: 0.074 ± 0.107 mm, Y: 0.168 ± 0.176 mm, and Z: -0.003± 0.155 mm. The results of paired t-test were X and Z: p >0.05, Y: p <0.05.
  
  
  CONCLUSIONS
  By using contact measurement and the reference point system alignment technique, highly accurate reconstruction of the vertical distance and centric relation of a digital edentulous jaw model can be achieved, which meets the design and manufacturing requirements of the complete dentures. The error of horizontal anterior/posterior jaw relation was relatively large.
authors: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China; Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China; Research Center of Engineering and Technology for Digital Dentistry, Ministry of Health, Beijing, China.
authors: Weiwei
authors: W
authors: Li
authors: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China; Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China; Research Center of Engineering and Technology for Digital Dentistry, Ministry of Health, Beijing, China.
authors: Fusong
authors: F
authors: Yuan
authors: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China; Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China; Research Center of Engineering and Technology for Digital Dentistry, Ministry of Health, Beijing, China.
authors: Peijun
authors: P
authors: Lv
authors: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China; Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China; Research Center of Engineering and Technology for Digital Dentistry, Ministry of Health, Beijing, China.
authors: Yong
authors: Y
authors: Wang
authors: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China; Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China; Research Center of Engineering and Technology for Digital Dentistry, Ministry of Health, Beijing, China.
authors: Yuchun
authors: Y
authors: Sun
mesh_terms: D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007568:Jaw / Q000473:pathology*; D007575:Jaw, Edentulous / Q000473:pathology*; D008297:Male