1. Department of Dentistry and Oral Surgery, Unit of Sensory and Locomotor Medicine, Division of Medicine, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
2. Department of Surgical Pathology, Shimane University Hospital, Shimane 693-8501, Japan
3. Department of Oral and Maxillofacial Surgery, Matsue City Hospital, Shimane 690-8509, Japan
4. Department of Oral and Maxillofacial Surgery, Shimane University Faculty of Medicine, Shimane 693-8501, Japan