Received: 30 December 2018
Accepted: 28 February 2019
First Online: 1 April 2019
Ethics approval and consent to participate
: The study was conducted according to the dictates of the Declaration of Helsinki and was approved by the Ethical Review Board of Yonsei University Dental Hospital Institutional Review Board (IRB No. 2-2018-0048). Informed consent was waived due to the retrospective nature of the study. All authors had access to the study data and reviewed and approved this study.
: The method of this retrospective case report posed no more than “minimal risks” and that collection of data through noninvasive procedures (not including anesthesia or sedation) routinely employed in clinical practice and research including materials (data, documents, records, or specimens) that have been collected or will be collected solely for nonresearch purposes (such as medical treatment or diagnosis). Therefore, authors considered that consent for publication could be waived by the IRB.
: The authors declare that they have no competing interests.
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