1. Department of Periodontology Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology Beijing China
2. Department of Endocrinology Beijing Hospital, National Center of Gerontology Beijing China
3. Department of Stomatology Beijing Hospital, National Center of Gerontology Beijing China