Text and Data Mining valid from 2019-06-28
Received: 28 October 2018
Accepted: 22 June 2019
First Online: 28 June 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board at the Nara Medical University (Approval Number 325-2). All participants and/or their parents provided written informed consent for their participation in the study.
: Not applicable.
: The authors declare that they have no competing interests.