Text and Data Mining valid from 2019-11-04
Received: 25 December 2018
Accepted: 21 October 2019
First Online: 4 November 2019
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the Ethical Committee of the Tohoku University Graduate School of Dentistry (number: 23–4). Informed consent was obtained from all individual participants included in the study.
: Not applicable.
: The authors declare that they have no competing interests.