1. Department of Preventive and Community Dentistry, N330, DSB, College of Dentistry, The University of Iowa, Iowa City, Iowa 52242
2. Department of Periodontics and Dows Institute for Dental Research, College of Dentistry, The University of Iowa
3. Research Fellow, Dental Research Unit, Health Research Council, Wellington School of Medicine, Wellington, New Zealand
4. Dows Institute for Dental Research, College of Dentistry, The University of Iowa
5. Department of Pediatric Dentistry and Dows Institute for Dental Research, College of Dentistry, The University of Iowa