1. Department of Oral Surgery, Oral Sciences, Clinical Dentistry, Institute of Biomedical SciencesTokushima University Graduate School Tokushima 770‐8504 Japan
2. Department of Biomaterials, Faculty of Dental ScienceKyushu University Fukuoka 812‐8582 Japan
3. Division of Maxillofacial Diagnostic and Surgical Sciences, Section of Oral and Maxillofacial Surgery, Faculty of Dental ScienceKyushu University Fukuoka 812‐8582 Japan