1. Postgraduate student, Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
2. Resident, Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
3. Resident, Department of Stomatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
4. Research Assistant, Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China.
5. Research Assistant, Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
6. Professor and Chair, Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China.