1. Department of Stomatology, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, China
2. Department of Periodontology, Changsha Stomatological Hospital, Hunan University of Traditional Chinese Medicine, Changsha 410004, China
3. Department of Periodontology, Tianjin Stomatological Hospital and Tianjin Key Laboratory of Oral Function Reconstruction, Hospital of Stomatology, Nankai University, Tianjin 300041, China
4. Department of Stomatology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China