Biological derivation of a range of cephalometric norms for children of African American descent (after Steiner)

Abstract

The purpose of this study was to report a normal range of anteroposterior apical base differences and concomitant interincisor inclinations and locations derived from a sample of American children (12 to 16 years) of African descent with normal occlusion (statistically defined). Standard cephalometric radiographs of 40 boys and 40 girls were traced and the Steiner Analysis performed. In addition to the ANB angle, 6 supplemental anteroposterior apical base separation estimators were measured, mean values established, and correlation (r ) associations performed. The range of anteroposterior apical base difference was –0.5° to 9.5° estimated by the ANB angle or a linear distance of ±6.5 mm using the Wits Appraisal. The angular and linear distance of the upper incisor to NA line (compensations) ranged from a low of 12° and 3 mm to a high of 39° and 14 mm. The angular and linear distance of the lower incisor to the NB line ranged from a low of 17° and 3 mm to a high of 47.5° and 17.5 mm. Biologically, the results suggested a wide range of equally acceptable sagittal apical base relationships and associated compensations in upper and lower incisor inclinations; normal occlusion was viewed as the reference point. Considering the usage of such descriptive terms as “ideal,” “acceptable compromises,” and “individualized treatment goals,” to describe the angulation and inclination of the incisor teeth, the need for a distinction between biologically derived reference norms and esthetic preference reference norms is apparent when analyzing normal occlusion. (Am J Orthod Dentofacial Orthop 2000;117:90-101)