1 Department of Psychosomatic Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. totoompm@tmd.ac.jp.
2 Department of Psychosomatic Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. risaompm@tmd.ac.jp.
3 Department of Psychosomatic Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. toyoompm@tmd.ac.jp.
4 Department of Basic Dental Sciences, Faculty of Odonto-Stomatology, University of Medicine And Pharmacy at Ho Chi Minh City, Ho Chi Minh, Vietnam. tu.ompm@tmd.ac.jp.