1. West China College of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases; No.14, Third Section, Renmin Nan Road Chengdu Sichuan China 610041
2. West China Hospital, Sichuan University; Chinese Cochrane Centre, Chinese Clinical Trial Registry, Chinese Evidence-Based Medicine Centre, INCLEN Resource and Training Centre; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
3. Lanzhou University; Evidence-Based Medicine Center, School of Basic Medical Sciences; 199 Don Gang West Road Chengguan District Lanzhou City China 730000 Lanzhou City
4. Sichuan University; West China Medical School; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
5. West China Second University Hospital, West China Women's and Children's Hospital; Department of Clinical Medicine; No. 17, Section Three Ren Min Nan Lu Avenue Chengdu Sichuan China 610041
6. West China Hospital, Sichuan University; Chinese Cochrane Centre, Chinese Evidence-Based Medicine Centre; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041