Critical evaluation of the ANB angle.

It has been demonstrated, first, in an empirical manner (qualitatively) and, second, in a geometric-mathematical manner (quantitatively) that the ANB angle depends not only on the anteroposterior relationship of the jawbones (which it should measure) but also on the maxillary inclination and maxillary prognathism, and slightly on the facial dimensions. Faces having the same anteroposterior value for the jawbones can have very different ANB angles (Figs. 3 and 4) and vice versa.