Read at the January, 1975 meeting of the Midwestern Component of the Angle Society.

Supported financially in part by the National Institutes of Health Grant 5SO1FR05302-06.

From the Department of Orthodontics, Loma Linda Univ., Lorna Linda, California.

Given at the January, 1973 meeting of the North Atlantic Component of the Angle Society.

Read before the Northern California Component of Angle Society, January 1973.

From the Department of Orthodontics, Dental Faculty, University of Bergen, Bergen, Norway.

Read before the Eastern Component of the Angle Society, March, 1975.

From the Dental Research Institute, Univ. of Michigan and the Orthodontic Department, Univ. of Nymegen. This study was supported, in part, by a grant to the Nymegen Growth Study from “Het Praeventiefonds,” The Hague, The Netherlands.