1. Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
2. Department of Dentistry and Oral Surgery, Osaka Rosai Hospital, Sakai, Osaka 591-0825, Japan
3. Department of Cardiovascular Surgery, Osaka Rosai Hospital, Sakai, Osaka 591-0825, Japan
4. Department of Oral Frontier Biology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan