Department of Anatomy, College of Physicians and Surgeons, and Division of Orthodontics, School of Dental and Oral Surgery, Columbia University, New York.

Aided, in part, by Grant NB-00965, National Institute of Neurological Diseases and Blindness, National Institutes of Health.

Presented before the Midwestern Component of the Angle Society, Chicago, 1966.

*From a thesis in partial fulfillment of the requirements for the degree of Master of Dental Science, Tufts Univ. School of Dental Medicine.

From the School of Dentistry, West Virginia University.

This investigation was supported (in part) by a Public Health Service training grant No. 5T1 DE 1-09 from the College of Dentistry, University of Pennsylvania, Public Health Service and by grant No. DE-02172 from the National Institute of Dental Research.