1. Women’s and Children’s Health Section, Division of Public Health, Raleigh, NC, USA
2. Birth Defects Monitoring Program, Division of Public Health, State Center for Health Statistics, Raleigh, NC, USA
3. Departments of Pediatrics and Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
4. Division of Plastic, Maxillofacial, and Oral Surgery, Duke University, Durham, NC, USA
5. School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
6. Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
7. School of Dentistry and Office of the Provost, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA