Feng, Xin
Chen, Yicheng
Hellén-Halme, Kristina
Cai, Weihua
Shi, Xie-Qi
Article History
Received: 15 December 2020
Accepted: 4 March 2021
First Online: 17 March 2021
Declarations
:
: The study was approved by the ethics committee of China (DLKQLL201604, Dalian Stomatological Hospital) as well as the ethics committee of Norway (2018/1547 REK Vest, University of Bergen). Written informed consent was obtained from all participants or their legal guardians.
: Not applicable as there are no participants’ identifiable data, picture or illustrations that require consent to publish in this manuscript.
: The authors declare that they have no competing interest.