title: Cephalometric study to test the reliability of anteroposterior skeletal discrepancy indicators using the twin block appliance.
abstract: BACKGROUND
  The objectives of this study were to check the reliability of the five angular and two linear parameters for sagittal maxillo-mandibular discrepancy and to compare and correlate angular parameters with the ANB angle, and the linear parameter with Wits analysis.
  
  
  METHODS
  The pre-treatment and post-functional lateral cephalograms of 25 subjects (17 males, 8 females) with class II division 1 malocclusion treated with twin block functional appliance were selected. Five angular (ANB, β angle, APDI, YEN angle, W angle) and two linear (Wits analysis, App-Bpp) parameters were traced on both sets of cephalograms. Paired Student's t-test, one-way ANOVA, post hoc test, and Karl Pearson correlation statistical analysis were performed.
  
  
  RESULTS
  All the parameters considered in our study showed highly significant difference in pre-treatment and post-functional values, suggesting their reliability (p < 0.0001). When ANB angle was compared with the other angular parameters, a highly significant change in the mean value of the difference in pre-treatment (T1) and post-functional (T2) values was noted (p < 0.001). No significant change was seen when comparing the mean value of the difference in T1 and T2 between linear parameters (p = 0.949).
  
  
  CONCLUSIONS
  All the parameters used in the study can be reliably used to assess anteroposterior skeletal discrepancy. Whenever limitations of the ANB angle and Wits analysis are foreseen, the W angle and App-Bpp, respectively, can be reliably used. The YEN angle may reliably predict the post-functional change with the use of twin block appliance.
authors.forename: Rahul
authors.initials: R
authors.lastname: Trivedi
authors.forename: Amit
authors.initials: A
authors.lastname: Bhattacharya
authors.forename: Falguni
authors.initials: F
authors.lastname: Mehta
authors.forename: Dolly
authors.initials: D
authors.lastname: Patel
authors.forename: Harshik
authors.initials: H
authors.lastname: Parekh
authors.forename: Vaibhav
authors.initials: V
authors.lastname: Gandhi
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002508:Cephalometry / Q000706:statistics & numerical data*; D002648:Child; D002680:Chin / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000473:pathology / Q000628:therapy; D008334:Mandible / Q000473:pathology*; D008335:Mandibular Condyle / Q000473:pathology; D008437:Maxilla / Q000473:pathology*; D009295:Nasal Bone / Q000473:pathology; D016382:Orthodontic Appliance Design; D017289:Orthodontic Appliances, Functional / Q000706:statistics & numerical data*; D057887:Overbite / Q000473:pathology / Q000628:therapy; D015203:Reproducibility of Results; D012658:Sella Turcica / Q000473:pathology