1. Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Niigata 951-8514, Japan
2. Oral Rehabilitation, Niigata University Medical and Dental Hospital, Niigata, Niigata 951-8520, Japan
3. Department of Dentistry, Oral and Maxillofacial Surgery, Kansai Rosai Hospital, Amagasaki, hyougo 660-8511, Japan
4. Division of Comprehensive Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata,Niigata 951-8514, Japan