Received: 14 April 2021
Accepted: 27 August 2021
First Online: 7 September 2021
: Ethical approval (Approval No: PKUSSIRB-201942018) for the study was received from Peking University Stomatological Hospital Biomedical Ethics Committee and written informed consent was obtained from each participant. In the case of minor participants, the consent of their legal guardians was also obtained. All procedures were performed in accordance with relevant guidelines.
: Not applicable.
: We declare no competing interests.