1. Division of Oral Biology, School of Dentistry, University of Leeds, Leeds LS9 7TF, UK
2. Department of Oral Medicine and Periodontology, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt
3. Leeds Institute of Rheumatic and Musculoskeletal Medicine, School of Medicine, University of Leeds, Leeds LS9 7TF, UK
4. Department of Oral Pathology, Faculty of Dentistry, Suez Canal University, Ismailia 41522, Egypt