1. Department of Oral and Maxillary Surgery, Beijing Stomatological Hospital, Capital Medical University, Beijing, 100050, P.R. China
2. Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China
3. Department of Engineering Physics, Tsinghua University, Beijing, 100084, P.R. China
4. Nuctech Company Limited, Beijing, 100084, P.R. China