1. a PhD Student, Discipline of Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China; Attending Orthodontist, Department of Orthodontics and Key Lab for Oral Biomedical Engineering, School of Stomatology, Wuhan University, Wuhan, Hubei, China.
2. b Professor, Discipline of Dental Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
3. c Chair and Professor, Discipline of Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.