1. Department of Advanced Medicine Dentistry and Dental/OralSurgery, Japanese National Center for Geriatrics and Gerontology, Obu, Japan.
2. Division of Clinical Oral Rehabilitation, The Nippon Dental University Graduate School of Life Dentistry at Tokyo, Chiyoda-ku, Tokyo, Japan.
3. Department of Palliative and Supportive Care, Palliative Care Team and Seirei Hospice, Seirei Mikatahara General Hospital, Hamamatsu, Japan.