1. Independent Unit of Propaedeutic and Dental Physical Diagnostics, Faculty of Medicine and Dentistry, Pomeranian Medical University, Rybacka 1, 70-204 Szczecin, Poland
2. Department of Econometrics, Faculty of Economic Sciences, Koszalin University of Technology, Kwiatkowskiego 6e, 75-343 Koszalin, Poland
3. Scientific Unit of Dysfunction of the Masticatory System, Chair and Department of Prosthodontics, Faculty of Medicine and Dentistry, Pomeranian Medical University, Rybacka 1, 70-204 Szczecin, Poland