Floating norms for the ANB angle as guidance for clinical considerations.

If the ANB angle is used in cephalometric analyses, its individual nature should be recognized. A method to interpret the measured values of the ANB angle has been recently presented by Hussels and Nanda. This article introduces another method to evaluate the appropriateness of the measured values. A regression analysis was applied to explain the individual variation of the ANB angle in a sample of 55 untreated orthodontic patients, aged 7 to 14 years, with Class I (Angle) malocclusion. Approximately 63% of the variation of the ANB angle could be explained by the variation of the SNA and NSL/ML angles. The regression produced a list of floating norms of the ANB angle for different facial types. The floating norms can help to interpret the individual normal variation of the ANB angle.