1. Department of Dental Anaesthesiology; Okayama University Hospital; Okayama Japan
2. Department of Dental Anaesthesiology and Special Care Dentistry; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama Japan
3. Center for Promotion of Dental Education and International Collaboration; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama Japan