title: Computational formulation of orthodontic tooth-extraction decisions. Part I: to extract or not to extract.
abstract: OBJECTIVE
  To develop a mathematical model that simulates whether or not to extract teeth in optimizing orthodontic treatment outcome and to formulate the morphologic traits sensitive to optimizing the tooth-extraction/nonextraction decisions.
  
  
  METHODS
  A total of 188 conventional orthodontic records of patients with good treatment outcomes were collected, and dentofacial morphologic traits, along with their degrees of influence in the optimized model, were determined.
  
  
  RESULTS
  The rate of coincidence between the recommendations given by the optimized model and the actual treatments performed was found to be 90.4%. The major morphologic traits and their corresponding influences in improving the simulation accuracy of the model were the incisor overjet (3.0) and the size of the basal arch relative to the sum of the mesiodistal crown diameters of the upper dentition (2.4) and the lower dentition (2.0). The remaining 22 morphologic-trait variables were also found to be indispensable in achieving robust simulation readings.
  
  
  CONCLUSIONS
  A mathematical model that simulates whether or not to extract teeth in optimizing orthodontic treatment outcomes with a success rate of 90.4% at its prediction performance was developed. This model has 25 morphologic traits with four major categories (sagittal dentoskeletal and soft tissue relationship, vertical dentoskeletal relationship, transverse dental relationship, and intra-arch conditions) that affected the accuracy in determining optimal tooth extractions/nonextractions.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Japan. opam@dent.osaka-u.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Takada
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yagi
authors.forename: Eriko
authors.initials: E
authors.lastname: Horiguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003198:Computer Simulation; D003661:Decision Support Techniques; D003724:Dental Arch / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008310:Malocclusion / Q000628:therapy*; D008962:Models, Theoretical; D009971:Orthodontics, Corrective / Q000379:methods*; D012372:ROC Curve; D019228:Tooth Crown / Q000033:anatomy & histology; D014081:Tooth Extraction; D055815:Young Adult