This study was supported by the Minnesota Dental Foundation and the Graduate School of the University of Minnesota (Grant No. 417-0303-4909-2).

From the Division of Orthodontics, School of Dentistry, University of Minnesota.

The implants were placed by Dr. Norman O. Holte of the Oral Surgery Division.

*Read before the Northern California Component of the Angle Society, March 1963. Supported in part by USPHS grant No. D-1085.

*This thesis is submitted to the Faculty of the Graduate School of Medicine of the University of Pennsylvania in partial fulfillment of the requirements for the Degree of Master of Science in Dentistry, 1961.

* Department of Orthodontics, University of Bologna.

Division of Orthodontics, School of Dental and Oral Surgery, Columbia University, New York.

This investigation was supported in part by Public Health Service Research Grant No. 1S01FR0503101 from the National Institute of Health.