1. Center of Oral Clinical Examination Hiroshima University Hospital Hiroshima Japan
2. Department of Oral & Maxillofacial Pathobiology, Graduate School of Biomedical and Health Sciences Hiroshima University Hiroshima Japan
3. Department of Pathology Hiroshima Red Cross Hospital & Atomic‐bomb Survivors Hospital Hiroshima Japan
4. Department of Pathology and Laboratory Medicine Nagoya University Hospital Nagoya Japan
5. Department of Anatomic Pathology Tokyo Medical University Tokyo Japan