1. Department of Oral and Maxillofacial Surgery National Center for Global Health and Medicine Shinjuku‐ku Tokyo Japan
2. Department of Pathology National Center for Global Health and Medicine Shinjuku‐ku Tokyo Japan
3. Department of Hematology National Center for Global Health and Medicine Shinjuku‐ku Tokyo Japan
4. Department of Oral and Maxillofacial Surgical Oncology, Graduate School of Medical and Dental Sciences Tokyo Medical and Dental University Bunkyo‐ku Tokyo Japan