1. State Key Laboratory of Oral Diseases; West China College of Stomatology; Sichuan University; Chengdu Sichuan China
2. Department of Periodontics; West China Hospital of Stomatology; Sichuan University; Chengdu Sichuan China
3. Department of Stomatology; University of Electronic Science and Technology of China Hospital; Chengdu Sichuan China
4. Department of Epidemiology and Biostatistics; School of Public Health; Curtin University; Perth WA Australia