Funding for this research was provided by:
The Natural Science Foundation for Young Scientists of China (31800818)
the Program for the Natural Science Foundation of Chongqing (cstc2018jcyjAX220)
the Program for Innovation Team Building at Institutions of Higher Education in Chongqing (no)
Text and Data Mining valid from 2019-12-01
Received: 1 August 2019
Revised: 29 October 2019
Accepted: 4 November 2019
First Online: 18 December 2019
Ethics approval and consent to participate
: All research procedures were approved by the Medical Ethics Committee of the School of Stomatology, Chongqing Medical University, Chongqing, China (2019023), and written informed consent was obtained from all study participants.
: Not applicable.
: The authors declare that they have no competing interests.