1. Department of Oral and Maxillofacial Diseases; Helsinki University Hospital and University of Helsinki; Helsinki Finland
2. Department of Periodontology; Center for Clinical Research, General Dentistry; H. M. Goldman School of Dental Medicine; Boston University; Boston MA USA
3. Otorhinolaryngology/Maxillofacial Surgery; Kuopio University Hospital; Kuopio Finland
4. Preventive Cardiology, Internal Medicine; University of Michigan; Ann Arbor MI USA
5. Department of Public Health; University of Massachusetts; Lowell MA USA
6. Endodontics; H. M. Goldman School of Dental Medicine; Boston University; Boston MA USA
7. Edinburgh Dental Institute; University of Edinburgh; Scotland UK