Cephalometric floating norms for Czech adults.

The purpose of this study was to establish floating cephalometric norms for the description of the individual skeletal pattern in Czech adults. Floating norms provide a method of analysis that uses the variability of the associations among suitable cephalometric measures, on the basis of the regression model combining both sagittal and vertical skeletal parameters. Harmony box is a simple and useful tool for diagnostics of orthodontic anomalies according to individual cephalometric norms. 118 subjects, 53 male and 65 female, from Czech population were selected. The method of multiple regression analysis was used to determine interdependence among five cephalometric variables of the sample. Linear regression equations with corresponding r2 and standard error of the estimate (SE) were then illustrated as the harmony box. The results construct a harmony box based on correlated cephalometric variables. The multiple regression analysis of the data is graphically illustrated as a harmony schema which divides harmony box in three zones according to the type of the face - prognathic, orthognathic and retrognathic. The cephalometric floating norms describing the individual craniofacial pattern among Czech adults were established based on five correlated variables in the form of a harmony box.