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

The purpose of this study was to report a normal range of anteroposterior a pical base differences and concomitant interincisor inclinations and locati ons derived from a sample of American children (12 to 16 years) of African descent with normal occlusion (statistically defined). Standard cephalometr ic radiographs of 40 bays and 40 girls were traced and the Steiner Analysis performed. In addition to the ANB angle, 6 supplemental anteroposterior ap ical base separation estimators were measured, mean values established, and correlation (r) associations performed. The range of anteroposterior apica l base difference was -0.5 degrees to 9.5 degrees estimated by the ANB angl e or a linear distance of +/-6.5 mm using the Wits Appraisal. The angular a nd linear distance of the upper incisor to NA line (compensations) ranged f rom a low of 12 degrees and 3 mm to a high of 39 degrees and 14 mm. The ang ular and linear distance of the lower incisor to the NE line ranged from a low of 17 degrees and 3 mm to a high of 47.5 degrees and 17.5 mm. Biologica lly, the results suggested a wide range of equally acceptable sagittal apic al base relationships and associated compensations in upper and lower incis or inclinations; normal occlusion was viewed as the reference point. Consid ering the usage of such descriptive terms as "ideal,'' "acceptable compromi ses:' and "individualized treatment goals:' to describe the angulation and inclination of the incisor teeth, the need for a distinction between biolog ically derived reference norms and esthetic preference reference norms is a pparent when analyzing normal occlusion.