1. University of Witten/Herdecke, Germany
2. Department of Surgery, Columbia University - New York Presbyterian Hospital, New York, USA
3. Department of Oral and Maxillofacial Surgery, The Center for Oral Facial and Head Pain, Columbia University - New York Presbyterian Hospital, New York, USA
4. Humboldt University of Berlin, Berlin, Germany, and
5. Department of Neurology, The Center for Oral Facial and Head Pain, Columbia University - New York Presbyterian Hospital, New York, USA