1. aInstructor, Department of Orthodontics, School and Hospital of Stomatology, Peking University, Beijing, People's Republic of China
2. bProfessor, Department of Orthodontics, School and Hospital of Stomatology, Peking University, Beijing, People's Republic of China
3. cProfessor, Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing, People's Republic of China