*Read before the Edward H. Angle Society of Orthodontia, Washington, D.C., October, 1957.

*Read before the Edward H. Angle Society of Orthodontia, Washington, D.C., October, 1957.

*Read before the Edward. H. Angle Society of Orthodontia, Washington, D. C., October, 1957.

*Thesis presented in partial fulfillment of the requirements for the degree of Master of Science, Ohio State University, 1958.

*This investigation was supported by a research grant from the Division of Research Grants and Fellowships of the National Institutes of Health, United States Public Health Service.

Orthodontic Dept., Marquette University School of Dentistry, Milwaukee, Wisc.

The investigative portion of this paper was supported in part by a research grant, D-217, from the Institute for Dental Research of the National Institutes of Health, Public Health Service.