[Measurement errors in 2D cephalometrics].

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.