1 Department of Orthodontics, University of Homburg, Saar, Germany; Private Practice of Orthodontics in Traben-Trarbach, Germany. bludwig@kieferorthopaedie-mosel.de.
2 Department of Orthodontics, University of Puthisastra, Phnom Penh, Cambodia.
3 Private Practice of Orthodontics in in Bad Essen, Germany; Department of Orthodontics, Hannover Medical School, Hannover, Germany.
4 Division of Orthodontics, Department of Craniofacial Sciences, University of Connecticut School of Dental Medicine, Farmington, CT.