title: Automatic extraction of mandibular bone geometry for anatomy-based synthetization of radiographs.
abstract: We present an automatic method for segmenting Cone-Beam Computerized Tomography (CBCT) volumes and synthetizing orthopantomographic, anatomically aligned views of the mandibular bone. The model-based segmentation method was developed having the characteristics of dental CBCT, severe metal artefacts, relatively high noise and high variability of the mandibular bone shape, in mind. First, we applied the segmentation method to delineate the bone. Second, we aligned a model resembling the geometry of orthopantomographic imaging according to the segmented surface. Third, we estimated the tooth orientations based on the local shape of the segmented surface. These results were used in determining the geometry of the synthetized radiograph. Segmentation was done with excellent results: with 14 samples we reached 0.57+/-0.16 mm mean distance from hand drawn reference. The estimation of tooth orientations was accurate with error of 0.65+/-8.0 degrees. An example of these results used in synthetizing panoramic radiographs is presented.
authors.affiliation: Laboratory of Mathematics in Imaging, Brigham and Women's Hospital, Harvard Medical School, USA. kari.antila@vtt.fi
authors.forename: Kari
authors.initials: K
authors.lastname: Antila
authors.forename: Mikko
authors.initials: M
authors.lastname: Lilja
authors.forename: Martti
authors.initials: M
authors.lastname: Kalke
authors.forename: Jyrki
authors.initials: J
authors.lastname: Lötjönen
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008334:Mandible / Q000000981:diagnostic imaging*; D010363:Pattern Recognition, Automated / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011861:Radiography, Dental / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*