Received: 7 March 2021
Accepted: 10 June 2021
First Online: 17 July 2021
: This retrospective study was approved by the institutional review board of Gangneung-Wonju National University Dental Hospital (GWNUDH-IRB2019-A009).
: Written informed consent was obtained from the patients or patient’s guardian for including the data of radiographic images in this study.
: I have no conflict of interest to declare.