1. Department of Oral and Maxillofacial Surgery, National Center for Global Health and Medicine, Tokyo, Japan.
2. Biostatistics Section, Clinical Research Center, Chiba University Hospital, Chiba, Japan.
3. Faculty of Nursing, Japanese Red Cross College of Nursing, Tokyo, Japan.
4. Department of Hematology, National Center for Global Health and Medicine, Tokyo, Japan.
5. Department of Oral and Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.