1. Department of Periodontics and Oral Medicine & Michigan Center for Oral Health Research; University of Michigan School of Dentistry; Ann Arbor MI USA
2. Department of Biostatistics; School of Public Health; University of Michigan; Ann Arbor MI USA
3. Department of Periodontology; School of Dental Medicine; University of Bern; Bern Switzerland
4. Department of Biomedical Engineering; College of Engineering; University of Michigan; Ann Arbor MI USA