Funding for this research was provided by:
Young Scientists Fund (20151131200389)
Sichuan Province Science and Technology Support Program (2016JY0006)
Text and Data Mining valid from 2019-11-21
Received: 23 October 2019
Accepted: 5 November 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: This study was approved by the ethics committee of the West China Hospital of Stomatology, Sichuan University (2012022). All people in both groups voluntarily signed informed consent before joining this study.
: Not applicable.
: The authors declare that they have no competing interests.