1. Department of Oral health Sciences, Otemae Junior College, Japan
2. Department of Oral and Maxillofacial Surgery, National Center for Global Health and Medicine, Japan
3. Faculty of Nursing, Japanese Red Cross College of Nursing, Japan
4. AIDS Clinical Center, National Center for Global Health and Medicine, Japan
5. Division of Oral and Maxillofacial Surgery, Faculty of Dentistry & Graduate School of Medical and Dental Sciences, Niigata University, Japan