Received: 4 June 2021
Accepted: 11 October 2021
First Online: 10 November 2021
: This study was conducted according to the guidelines laid down in the Declaration of Helsinki, and all procedures involving research study participants were approved by the Ajou Medical Center Institutional Review Board (approval number AJIRB-MED-MDB-20-123). Because of the study’s retrospective nature, Ajou Medical Center Institutional Review Board specifically waived the requirement to obtain parental or guardian informed consent to conduct this study.
: Not Applicable.
: All authors declare that they have no competing interests.