title: A Method of Three-Dimensional Recording of Mandibular Movement Based on Two-Dimensional Image Feature Extraction.
abstract: OBJECTIVE
  To develop a real-time recording system based on computer binocular vision and two-dimensional image feature extraction to accurately record mandibular movement in three dimensions.
  
  
  METHODS
  A computer-based binocular vision device with two digital cameras was used in conjunction with a fixed head retention bracket to track occlusal movement. Software was developed for extracting target spatial coordinates in real time based on two-dimensional image feature recognition. A plaster model of a subject's upper and lower dentition were made using conventional methods. A mandibular occlusal splint was made on the plaster model, and then the occlusal surface was removed. Temporal denture base resin was used to make a 3-cm handle extending outside the mouth connecting the anterior labial surface of the occlusal splint with a detection target with intersecting lines designed for spatial coordinate extraction. The subject's head was firmly fixed in place, and the occlusal splint was fully seated on the mandibular dentition. The subject was then asked to make various mouth movements while the mandibular movement target locus point set was recorded. Comparisons between the coordinate values and the actual values of the 30 intersections on the detection target were then analyzed using paired t-tests.
  
  
  RESULTS
  The three-dimensional trajectory curve shapes of the mandibular movements were consistent with the respective subject movements. Mean XYZ coordinate values and paired t-test results were as follows: X axis: -0.0037 ± 0.02953, P = 0.502; Y axis: 0.0037 ± 0.05242, P = 0.704; and Z axis: 0.0007 ± 0.06040, P = 0.952. The t-test result showed that the coordinate values of the 30 cross points were considered statistically no significant. (P<0.05).
  
  
  CONCLUSIONS
  Use of a real-time recording system of three-dimensional mandibular movement based on computer binocular vision and two-dimensional image feature recognition technology produced a recording accuracy of approximately ± 0.1 mm, and is therefore suitable for clinical application. Certainly, further research is necessary to confirm the clinical applications of the method.
authors.affiliation: 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.forename: Fusong
authors.initials: F
authors.lastname: Yuan
authors.affiliation: 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.forename: Huaxin
authors.initials: H
authors.lastname: Sui
authors.affiliation: The Second Artillery Engineering College, Xi'an, China.
authors.forename: Zhongke
authors.initials: Z
authors.lastname: Li
authors.affiliation: 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.forename: Huifang
authors.initials: H
authors.lastname: Yang
authors.affiliation: 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.forename: Peijun
authors.initials: P
authors.lastname: Lü
authors.affiliation: 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.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: 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.forename: Yuchun
authors.initials: Y
authors.lastname: Sun
mesh_terms: D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008334:Mandible / Q000502:physiology*; D009068:Movement; D012984:Software