1. Institute of Occupational and Social Medicine, RWTH Aachen University, Aachen, Germany.
2. Medical Commission of the Union Internationale des Associations d'Alpinisme (UIAA MedCom), Bern, Switzerland.
3. Department for Operative Dentistry, Periodontology and Preventive Dentistry, RWTH Aachen University, Aachen, Germany.
4. Dental Practice, Kleve, Germany.
5. Division of Oral Microbiology and Immunology, RWTH Aachen University, Aachen, Germany.
6. Department of Paediatrics, Imperial College, London, United Kingdom.