Funding for this research was provided by:
National Natural Science Foundation of China (81530069)
Guangdong Province Introduction of Innovative R&D Team (2009010058)
Received: 12 February 2020
Revised: 23 May 2020
Accepted: 13 July 2020
First Online: 31 July 2020
Ethics approval and consent to participate
: The informed consents were obtained from the parents or guardians, and the ethics approval was required according to the guidelines from the Ethics Committee of Hospital of Stomatology in Sun Yat-sen University. All the procedures described in this report were approved by the Ethics Committee of Hospital of Stomatology in Sun Yat-sen University.
: Not applicable.
: The authors declare that they have no competing interests.