1. Department of Oral and Maxillofacial Surgery, Graduate School of Biomedical and Health Sciences Hiroshima University Hiroshima Japan
2. Department of Public Oral Health, Program of Oral Health Sciences Hiroshima University Hiroshima Japan
3. Department of Dentistry, Oral and Maxillofacial Surgery National Hospital Organization Kure Medical Center and Chugoku Cancer Center Kure Japan
4. Department of General Dentistry Hiroshima University Hospital Hiroshima Japan