1. Department of Head & Neck Surgery – Maxillofacial Surgery, Otolaryngology & Ophthalmology, Prof Stanislaw Popowski Voivoid Children Hospital, Żołnierska 18 A10-561 Olsztyn, Poland
2. Faculty of Mechanical Engineering, Lublin University of Technology, Lublin, Poland
3. Department of Conservative Dentistry, Medical University of Warsaw, Warsaw, Poland