Tetsuya Yoda1, Tsuyoshi Sato2. 1. Department of Oral and Maxillofacial Surgery, Saitama Medical University, Saitama, Japan. Electronic address: yoda@saitama-med.ac.jp. 2. Department of Oral and Maxillofacial Surgery, Saitama Medical University, Saitama, Japan. Electronic address: tsato@saitama-med.ac.jp.