Assistant Professor, Department of Orthodontics, University of Oregon Dental School, Portland, Oregon.

From the Department of Orthodontics, University OP Illinois.

This was supported financially in part, National Institutes of Health Grant, #5 SO1 FR05302-06.

*Professor and Chairman, Department of Orthodontics, Loma Linda University.

From the Department of Orthodontics and Dental Research Institute, University of Michigan, Ann Arbor, Michigan.

Read before the Northern California Component of the Angle Society.

Based on a thesis submitted in partial fulfillment of the requirements for the Certificate in Orthodontics at the Royal Dental Hospital, University of London, 1968.

The nutrition survey was supported by contract MC-R-390050-06-0 from Maternal and Child Health Services, Department of Health, Education and Welfare.

This investigation was supported by NIH research grant number DE 02668 from the National Institute of Dental Research and by NIH grant number RR 05333 from the Division of Research Facilities and Resources.