By William R. Proffit, DDS, PhD, Department of Orthodontics, School of Dentistry, University of North Carolina, Chapel Hill, NC; Henry Fields, DDS, MS, MSD, Professor, OSU College of Dentistry; Chief, Orthodontics, Nationwide Children’s Hospital Department of Dentistry, Columbus, Ohio; Brent Larson, DDS, MS, Professor and Director, Division of Orthodontics, Assistant Dean for Advanced Education, Director of Graduate Studies, MS Dentistry, School of Dentistry, University of Minnesota, Minneapolis, Minnesota; David M. Sarver, DMD, MS, Adjunct Professor, University of North Carolina, Chapel Hill, NC and Private Practice, Birmingham, Alabama