Received: 25 April 2020
Accepted: 4 January 2021
First Online: 19 January 2021
Ethics approval and consent to participate
: The study was reviewed and approved by the Institutional Review Board (IRB) of Seoul National University School of Dentistry (approval No. S-D20190016). All participants were aware that they were taking part in this research and gave informed consent in writing in addition to confirming that they would allow us to use their collected data anonymously for publication. All the data were anonymously collected and analyzed.
: Not Applicable.
: All authors have no potential conflicts of interest.