1. Department of Prosthetic Dentistry, Faculty of Medicine, Dresden University of Technology, 01307 Dresden, Germany
2. Department of Prosthetic Dentistry, Faculty of Dentistry, Wroclaw Medical University, 50425 Wroclaw, Poland
3. Department of Maxillofacial Orthopedics and Orthodontics, Faculty of Dentistry, Wroclaw Medical University, 50425 Wroclaw, Poland
4. Department and Clinic of Rheumatology and Internal Medicine, Faculty of Medicine, Wroclaw Medical University, 50556 Wroclaw, Poland
5. Department of Prosthetic Dentistry, School of Dentistry, National Taiwan University, Taipei City 100, Taiwan