title: Application of photogrammetry for analysis of occlusal contacts.
abstract: BACKGROUND
  The conventional 2D-analysis methods for occlusal contacts provided limited information on tooth morphology. This present study aims to detect 3D positional information of occlusal contacts from 2D-photos via photogrammetry. We propose an image processing solution for analysis of occlusal contacts and facets via the black silicone method and a photogrammetric technique.
  
  
  METHODS
  The occlusal facets were reconstructed from a 2D-photograph data-set of inter-occlusal records into a 3D image via photogrammetry. The configuration of the occlusal surface was reproduced with polygons. In addition, the textures of the occlusal contacts were mapped to each polygon. DIFFERENCE FROM CONVENTIONAL METHODS: Constructing occlusal facets with 3D polygons from 2D-photos with photogrammetry was a defining characteristic of this image processing technique. It allowed us to better observe findings of the black silicone method. Compared with conventional 3D analysis using a 3D scanner, our 3D models did not reproduce the detail of the anatomical configuration. However, by merging the findings of the inter-occlusal record, the deformation of mandible and the displacement of periodontal ligaments under occlusal force were reflected in our model. EFFECT OR PERFORMANCE: Through the use of polygons in the conversion of 2D images to 3D images, we were able to define the relation between the location and direction of the occlusal contacts and facets, which was difficult to detect via conventional methods.
  
  
  CONCLUSIONS
  Through our method of making a 3D polygon model, the findings of inter-occlusal records which reflected the jaw/teeth behavior under occlusal force could be observed 3-dimensionally.
authors.affiliation: Department of Fixed Prosthodontics, School of Dental Medicine, Tsurumi University, 2-1-3, Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shigeta
authors.forename: Rio
authors.initials: R
authors.lastname: Hirabayashi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ikawa
authors.forename: Takuya
authors.initials: T
authors.lastname: Kihara
authors.forename: Eriko
authors.initials: E
authors.lastname: Ando
authors.forename: Shinya
authors.initials: S
authors.lastname: Hirai
authors.forename: Shunji
authors.initials: S
authors.lastname: Fukushima
authors.forename: Takumi
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D010780:Photogrammetry / Q000379:methods*