Fumio Ide1, Kentaro Kikuchi2, Yuji Miyazaki2, Kaoru Kusama2. 1. Division of Pathology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 350-0283, Japan. idef@dent.meikai.ac.jp. 2. Division of Pathology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 350-0283, Japan.