1. Department of Maxillofacial Surgery, Medical University of Lodz, 113 Żeromskiego Str., 90-549 Lodz, Poland
2. Department of Otolaryngology, Hospital in Sosnowiec, Zegadłowicza 3, 41-200 Sosnowiec, Poland
3. Department of Oral Surgery, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
4. 4th Military Clinical Hospital in Wroclaw, ul. Rudolfa Weigla 5, 50-981 Wroclaw, Poland
5. Department of Maxillofacial Surgery, Medical University of Gdansk, 80-210 Gdańsk, Poland