1. Departments of Dental Medicine; Kyoto Prefectural University of Medicine; Kyoto Japan
2. Department of Epidemiology for Community health and Medicine; Kyoto Prefectural University of Medicine; Kyoto Japan
3. Department of Neurology; Kyoto Prefectural University of Medicine; Kyoto Japan
4. Department of Pediatric Dentistry; Osaka University Graduate School of Dentistry; Osaka Japan
5. Department of Radiology; Kyoto Prefectural University of Medicine; Kyoto Japan
6. Kyoto Industrial Health Association; Kyoto Japan
7. Department of Stroke and Cerebrovascular Diseases; National Cerebral and Cardiovascular Center; Osaka Japan
8. Department of Neurology; University of Louisville; KY USA