The authors regret the following error. The second affiliation of the first author was omitted from the article. The corrected affiliations are as follows:

1. State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China;
2. School of Nursing, Chengdu University of Traditional Chinese Medicine, No. 1166 Liutai Road, Wenjiang District, Chengdu City, Sichuan province 611137, China.