title: Flaws in root resorption assessment algorithms: role of tooth shape.
abstract: BACKGROUND
  The purposes of this study were to analyze and critique the mathematical algorithms used in the clinical assessment of root resorption.
  
  
  METHODS
  Geometric constructions and derived mathematical expressions were used to investigate the influence of tooth shape on the relationships between tooth, root, and crown lengths and their respective sizes as measured on before and after radiographs. results: The ambiguities of root-loss assessment protocols are demonstrated.
  
  
  CONCLUSIONS
  Root resorption assessment algorithms are unsuited for their intended applications.
authors.affiliation: School of Dentistry, Indiana University, and of Mechanical Engineering, School of Engineering and Technology, Purdue University, Indianapolis 46202, USA. tkatona@iupui.edu
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Katona
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006801:Humans; D009811:Odontometry; D011861:Radiography, Dental; D015203:Reproducibility of Results; D012391:Root Resorption / Q000000981:diagnostic imaging*; D019237:Tooth Cervix / Q000033:anatomy & histology; D019228:Tooth Crown / Q000033:anatomy & histology; D014092:Tooth Root / Q000033:anatomy & histology / Q000473:pathology