1993–1995
M. Samii, Hannover, Germany (Neurosurgery)

1995–1997
N. Schwenzer, Tübingen, Germany (Oral & Maxillofacial Surgery)

1997–1999
W. Draf, Fulda, Germany (Otorhinolaryngology)

1999–2001
R. Fahlbusch, Erlangen, Germany (Neurosurgery)

2001–2003
J.-E. Hausamen, Hannover, Germany (Oral & Maxillofacial Surgery)

2003–2005
F. Bootz, Bonn, Germany (Otorhinolaryngology)

2005–2007
R. Schmelzeisen, Freiburg, Germany (Oral & Maxillofacial Surgery)