From the Department of Orthodontics, the University of Nymegen, The Netherlands.

From the Department of Communication Disorders, Emerson College, Boston, Massachusztts.

Presented at the North Atlantic Component of the Edward H. Angle Society of Orthodontics, January 1976.

From the Departments of the Pedodontics, Orthodontics and Roentgenology, Institute of Dentistry, University of Helsinki.

From the Department of Orthodontics, Central Dental Clinic, Luleå, and the Section for Maxillo-Facial Roentgenology, Department of Diagnostic Radiology, Central Hospital, Boden, Sweden.

From the Department of Orthodontics, University of Graz, Austria.

Department of Orthodontics, Faculty of Odontology, University of Göteborg, Sweden.

Presented before the Midwestern Component of the Angle Society, January, 1977.

Read at the February 1977 meeting of the Southern California Component of the Angle Society.

The work was supported in part by PHS Grants DE-02172-13 and IR231-DE-453701; Image enhancement performed under the auspices of the Energy Research and Development Administration under Contract W7405-ENG-36.

From the Departments of Orthodontics and Medical Genetics, Indiana University.