1. Department of Orthodontics, School of Dentistry, Box 357446, University of Washington, Seattle, Washington 98195-3446, USA
2. Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, USA
3. Department of Statistics, University of Florida, Gainesville, USA
4. Private practice, Orange Park, Florida, USA
5. Private practice, Halethorpe, Maryland, USA