Funding for this research was provided by:
National Natural Science Foundation of China (81872186, 81641105)
Natural Sciences Foundation of Fujian Province (2017J01520, 2018J1816)
Received: 29 April 2019
Accepted: 7 January 2020
First Online: 14 January 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Hospital of Stomotology, Fujian Medical University (Approval Number: FMUSS-17-003), and written informed consent was obtained from each participant. The study was carried out in accordance with the guidelines for the care and use of human specimens and animals, including in the approved protocol.
: Not applicable.
: The authors declare that they have no competing interests.