1. Department of Periodontics and Oral Medicine University of Michigan School of Dentistry Ann Arbor Michigan USA
2. Department of Oral and Craniomaxillofacial Surgery, Center for Dental Medicine University Medical Center Freiburg Freiburg Germany
3. Laboratory of Epithelial Biology University of Michigan School of Dentistry Ann Arbor Michigan USA
4. Department of Periodontology Institute of Odontology, The Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
5. Department of Biomedical Engineering, College of Engineering and Biointerfaces Institute University of Michigan Ann Arbor Michigan USA