1. Department of Diagnostic Pathology; Tsurumi University School of Dental Medicine; Yokohama Japan
2. Department of Pathology; Tsurumi University School of Dental Medicine; Yokohama Japan
3. Division of Pathology, Department of Diagnostic and Therapeutic Sciences; Meikai University School of Dentistry; Saitama Japan
4. Department of Endodontics and Clinical Cariology; Tokyo Dental College; Tokyo Japan