1. Department of Oral Health Sciences - Orthodontics; KU Leuven & Dentistry, University Hospitals Leuven; Belgium
2. Department of Orthodontics and Craniofacial Biology; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
3. Department of Oral Health Sciences - Periodontology; KU Leuven & Dentistry, University Hospitals Leuven; Belgium
4. Department of Quality of Medical Laboratories; Scientific Institute of Public Health; Brussels Belgium