1. Department of Stomatology, Bethune Hospital, (Shanxi Academy of Medical Sciences), Taiyuan City, Shanxi Province, China
2. Department of Stomatology, School of Stomatology, Shanxi Medical University, Taiyuan City, Shanxi Province, China
3. Department of Stomatology, The Community Health Service Center of Beijing Jiao Tong University, Beijing City, China
4. Department of Orthodontics, Shanxi Provincial People’s Hospital, Taiyuan City, Shanxi Province, China