1. Department of Dentistry and Oral-Maxillofacial Surgery, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
2. Department of Oral Science, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
3. Division of Clinical Oncology, Chiba Cancer Center, 666-2 Nitona, Chuo-ku, Chiba 260-8717, Japan
4. Division of Dentistry and Oral and Maxillofacial Surgery, Sammu Medical Center, 167 Naruto, Sammu, Chiba 289-1326, Japan
5. Department of Clinical Oncology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan