title: [Measurement errors in 2D cephalometrics].
abstract: The objective of this study is to analyze the influence that two parameters, the           source-subject distance and the type of receptor, have on the precision of localization of           the 19 most frequently employed cephalometric landmark points and then to analyze the           repercussions of localization errors on cephalometric measurements. The correct use of           profile cephalograms (norma lateralis) for clinical purposes depends essentially on the           precision of the identification and localization of the different landmark points that are           required for the elaboration of the various cephalometric analyses. For this study we           asked 53 orthodontists, selected at random, to identify 19 cephalometric points on           standard profile or digitized films taken at distances of 1 m 50 or of 4 m. The results we           obtained show no statistically significant differences in relation to the source-subject           distance or to the type of receptor. Each cephalometric landmark presented a           characteristic dispersion cloud; the most reliable points were primarily located on the           median sagittal plane. The cephalometric measurements that demonstrated the greatest           variability were associated with positions of the incisor apices, which makes their value           doubtful in the establishment of treatment plans and in ongoing evaluations of treatment           progress. For similar reasons, the worth of the Frankfort plane can be questioned when it           is compared to other, much more reliable cranial reference planes especially S-Na.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Bourriau
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bidange
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Foucart
mesh_terms: D002508:Cephalometry; D006801:Humans; D007180:Incisor; D011861:Radiography, Dental; D015203:Reproducibility of Results; D012886:Skull