title: Longitudinal growth changes of the cranial base from puberty to adulthood. A comparison of different superimposition methods.
abstract: OBJECTIVE
  To investigate the stability of cranial reference landmarks from puberty through adulthood and to compare the displacement of these landmarks among the superimposition methods of Björk, Ricketts, Steiner, and the proposed tuberculum sella-wing (T-W) reference line.
  
  
  METHODS
  The sample consisted of serial lateral cephalometric radiographs of 30 Class II division 1 patients taken at the pretreatment (T1; mean age, 11.98 years), posttreatment (T2; mean age, 15.32 years) and postretention (T3; mean age, 32.12 years) periods. All cephalometric radiographs were superimposed at the cranial base according to the overall superimposition methods of Björk, Ricketts, Steiner, and the T-W method. The horizontal and vertical displacements of cranial landmarks (nasion, wing, tuberculum sella, sella, basion, and pterygomaxillare) were assessed by paired t-test according to Björk's structural method. One-way analysis of variance (ANOVA) was used for comparison of the displacement of cranial landmarks among the superimposition methods.
  
  
  RESULTS
  The tuberculum sella and wing were the most stable cranial landmarks of the cranial base. The stability of sella and pterygomaxillare points were somewhat questionable. Nasion and basion were highly variable. The displacements of all cranial landmarks were similar between the Björk and T-W methods in all study periods. Most of the cranial landmarks displaced similarly in the horizontal direction among the methods. Vertically, the behaviors of the cranial landmarks were frequently different.
  
  
  CONCLUSIONS
  T-W is the most similar superimposition method to Björk's structural method; thus, it is a reliable method for examining overall facial changes.
authors.affiliation: Department of Orthodontics, University of Ankara, Turkey. mirzenarat@hotmail.com
authors.forename: Zuleyha Mirzen
authors.initials: ZM
authors.lastname: Arat
authors.forename: Hakan
authors.initials: H
authors.lastname: Türkkahraman
authors.forename: Jeryl D
authors.initials: JD
authors.lastname: English
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Gallerano
authors.forename: Jim C
authors.initials: JC
authors.lastname: Boley
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002508:Cephalometry / Q000379:methods*; D002648:Child; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008312:Malocclusion, Angle Class II / Q000503:physiopathology*; D011627:Puberty; D011859:Radiography; D012015:Reference Standards; D015203:Reproducibility of Results; D019291:Skull Base / Q000000981:diagnostic imaging / Q000254:growth & development*; D013382:Subtraction Technique