Funding for this research was provided by:
National Natural Science Foundation of China (81271144)
Shanxi “1331 Project” Key Innovative Research Team (TD201809)
Youth Fund of Shanxi Applied Basic Research (201801D221270)
Shanxi Medical University School and Hospital of Stomatology Fund (KY201803)
Text and Data Mining valid from 2020-04-03
Received: 25 October 2019
Accepted: 21 February 2020
First Online: 3 April 2020
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of the School of Stomatology, Shanxi Medical University (No.2017LL018). All participants signed the informed consent forms.
: Not applicable.
: The authors declare that they have no competing interests.