1. Department of Oral Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734‑8553, Japan
2. Center of Oral Clinical Examination, Hiroshima University Hospital, Hiroshima 734‑8553, Japan
3. Department of Oral and Maxillofacial Pathobiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734‑8551, Japan