1. Public Policy Center, College of Dentistry, University of Iowa, Iowa City, Iowa.
2. Public Policy Center, University of Iowa, Iowa City, Iowa.
3. Department of Epidemiology, University of Iowa, and works at the Iowa Registry for Congenital and Inherited Disorders, Iowa City, Iowa.
4. Congenital Malformations Registry, Troy, New York.
5. Bureau of Environmental and Occupational Epidemiology, New York State Department of Health, Troy, New York.
6. National Foundation for Facial Reconstruction, New York, New York.
7. Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas.