1. Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine; University of Michigan School; Ann Arbor Michigan
2. Department of Periodontics; University of Oklahoma Health Sciences Center; Oklahoma City Oklahoma
3. Department of Periodontics and Oral Medicine; University of Michigan School of Dentistry; Ann Arbor Michigan
4. Department of Oral and Craniomaxillofacial Surgery, Center for Dental Medicine; University Medical Center Freiburg; Freiburg Germany