1. Department of Orthodontics and DentoFacial Orthopedics, University Hospital of Liège, Belgium
2. Dental Biomaterials Research Unit, Faculty of Medicine, University of Liège, Belgium
3. Department of Periodontology and Oral Surgery, University Hospital of Liège, Belgium
4. Department of Biostatistics and Medico-Economic Information, University Hospital of Liège, Belgium