Read at the May 1978 meeting of the Northern California Component of the Angle Society.

From the departments of Orthodontics, Histology and Biostatistics, New York University College of Dentistry.

From the departments of Oral Diagnosis, Oral Medicine and Radiology, and Orthodontics. The Hebrew University–Hadassah Faculty of Dental Medicine.

From the Department of Orthodontics, Dental Wing, K.G.'s Medical College, Lucknow, India.

From the Orthodontic and Biomaterials Sections, Dental School, UCLA, Los Angeles.

From the departments of Orthodontics and Applied Mathematics, the Univ. of the Witwatersand.

From the departments of Orthodontics and Oral Surgery, Niigata University.