Funding for this research was provided by:
Science and Technology Department of Sichuan Province (2020YFS0087)
Sichuan University-Luzhou City cooperation program (2018CDLZ-14)
Article History
Received: 26 April 2020
Accepted: 17 January 2021
First Online: 22 January 2021
Ethics approval and consent to participate
: The data collected from the questionnaire does not contain any private information of the participants and written informed consent for publication was obtained from the volunteer who provided his smile photographs in the questionnaire and article. All of our work was approved by the Ethics Committee of the West China School of Stomatology from Sichuan University (WCHSIRB-D-2019-066) and applicable patient release was obtained. Relevant documents can be found in the supplementary material.
: Written informed consent for publication was obtained from the volunteer who provided his smile photographs in the questionnaire and article.
: We declare no potential conflicts of interest with respect to the authorship or publication of this manuscript.