title: Anterior cranial-base time-related changes: A systematic review.
abstract: BACKGROUND
  The anterior cranial base has long been considered a stable reference structure for superimposing radiographs. However, some studies have questioned its stability. Therefore, the purposes of this systematic review were to give an overview of the studies evaluating growth and development of the anterior cranial base, assess their methodologic quality, and evaluate their validity and accuracy.
  
  
  METHODS
  Medline, Embase, and Google Scholar were searched without limitations up to June 2013. Additionally, the bibliographies of the finally selected articles were hand searched to identify any relevant publications that were not identified before. The lowest levels of evidence accepted for inclusion were cohort and cross-sectional studies.
  
  
  RESULTS
  A total of 11 articles met all inclusion criteria. They were published between 1955 and 2009. The sample sizes of these studies ranged from 28 to 464 subjects. Their methodologic quality ranged from moderate to low.
  
  
  CONCLUSIONS
  Sella turcica remodels backward and downward, and nasion moves forward because of the increase in size of the frontal sinus. These events lead to a continuous increase in the length of the cranial base until adulthood. The presphenoid and cribriform plate regions can be considered stable after age 7, making them the best cranial-base superimposition areas.
authors: Postgraduate student, Department of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
authors: Mona
authors: M
authors: Afrand
authors: Postgraduate student, Department of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
authors: Connie P
authors: CP
authors: Ling
authors: Private practice, Edmonton, Alberta, Canada.
authors: Siamak
authors: S
authors: Khosrotehrani
authors: Associate professor and division head of orthodontics, Department of Dentistry, Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada. Electronic address: carlosflores@ualberta.ca.
authors: Carlos
authors: C
authors: Flores-Mir
authors: Assistant professor, Department of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
authors: Manuel O
authors: MO
authors: Lagravère-Vich
mesh_terms: D059925:Anatomic Landmarks / Q000000981:diagnostic imaging / Q000254:growth & development; D002508:Cephalometry / Q000706:statistics & numerical data*; D005626:Frontal Sinus / Q000000981:diagnostic imaging / Q000254:growth & development; D006801:Humans; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000254:growth & development; D011859:Radiography; D015203:Reproducibility of Results; D012658:Sella Turcica / Q000000981:diagnostic imaging / Q000254:growth & development; D019291:Skull Base / Q000000981:diagnostic imaging / Q000254:growth & development*; D013100:Sphenoid Bone / Q000000981:diagnostic imaging / Q000254:growth & development