1. Department of Biologic and Materials Sciences University of Michigan School of Dentistry 1210 Eisenhower Place Ann Arbor Michigan
2. Department of Pediatric Dentistry School and Hospital of Stomatology Peking University 22 South Avenue Zhongguancun Haidian District Beijing 100081 China
3. Department of Anthropology Pennsylvania State University University Park Pennsylvania 16802
4. Department of Biomedical Sciences Seoul National University College of Medicine 275‐1 Yongon‐dong, Chongno‐gu Seoul 110‐768 Korea
5. Department of Pedodontics Faculty of Dentistry Istanbul University Istanbul Turkey
6. Department of Paediatric Dentistry Women's and Children's Hospital 72 King William Road North Adelaide South Australia 5006 Australia
7. Department of Pediatric Dentistry School of Dentistry University of California San Francisco California