1. Wroclaw Medical University, Department of Maxillofacial Surgery, Wroclaw, Poland
2. Wroclaw Medical University, Department of Otolaryngology, Head and Neck Surgery, Wroclaw, Poland
3. Wroclaw Medical University, Faculty of Health Science, Department of Clinical Nursing, Wroclaw, Poland
4. Fourth Military Teaching Hospital, Department of Surgery, Wroclaw, Poland