1. Section of Dentistry and Oral Surgery, Gunma Prefectural Cancer Center, Japan
2. Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
3. Department of Oral and Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
4. Section of Gastroenterology, Gunma Prefectural Cancer Center, Japan
5. Section of Gastrointestinal Surgery, Gunma Prefectural Cancer Center, Japan
6. Section of Pathology, Gunma Prefectural Cancer Center, Japan