1. Departments of Pediatric Surgery, Pediatric Urology and Pediatric Orthopedics, DRK Children’s Hospital Siegen, Siegen, Germany.
2. Department of Oral and Maxillofacial Surgery, University Hospital Marburg, Marburg, Germany.
3. Private Practice PD Dr. Frank Halling, Gesundheitszentrum Fulda, Fulda, Germany.