1. Boston University Henry M. Goldman School of Dental Medicine; Boston MA USA
2. Neurological disorders and Stroke; SUNY Downstate Medical Center; Brooklyn NY USA
3. Department of internal medicine; University of Michigan; Ann Arbor MI USA
4. Otorhinolaryngology/Oral and Maxillofacial Surgery; Kuopio University; Kuopio Finland
5. Department of Biostatistics; Boston University; Boston MA USA
6. Department of Oral and Maxillofacial Diseases; Helsinki University Central Hospital, and Institute of Dentistry; University of Helsinki; Helsinki Finland
7. Forsyth Institute, Periodontology; Cambridge MA USA