1. School of Dentistry University of Michigan Ann Arbor Michigan USA
2. School of Dentistry Creighton University Omaha Nebraska USA
3. School of Dentistry Oregon Health and Science University Portland Oregon USA
4. The Forsyth Institute Cambridge Massachusetts USA
5. School of Dental Medicine East Carolina University Greenville North Carolina USA
6. Arizona School of Dentistry and Oral Health A. T. Still University Mesa Arizona USA