1. Division of Oral Physiology,
2. Removable Prosthodontics, Niigata University Graduate School of
Medical and Dental Sciences, 5274, Gakkocho-dori 2, Niigata 951-8514, Japan; and
3. Division of Orthodontics and Biomedical Engineering, Nagasaki
University Graduate School of Biomedical Sciences, 1-7-1, Sakamoto, Nagasaki
852-8588, Japan;