Presented before the North Atlantic Component of the Angle Society, Ft. Lauderdale, Florida, April 8, 1969.

From the University of Bergen, Orthodontic Department, Norway. The study has been supported by the Norwegian Research Council, Grant E-51.73-O.

Given before the Midwestern Component of the Angle Society, January, 1969.

Supported in part by P.H.S. Grants DE-02506-01, FR-15 and DE-0087-14 and the Elementary Particles Group of the Physics department at the University of Pennsylvania.

Taken in part from a thesis in partial fulfillment of the requirements for the degree of Master of Science, Loma Linda University, School of Dentistry.

From the Center for Human Growth and Development, University of Michigan and Fels Research Institute, Yellow Springs, Ohio