| Affiliation: | 1. Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing, China;2. Department of Periodontology, School and Hospital of Stomatology, Tianjin Medical University, Tianjin, China;3. Department of Stomatology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China;4. Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China;5. Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China |
