1. Independent Researcher, 07100 Sassari, Italy
2. Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy
3. Head and Neck Department, Surgery, Dentistry, Pediatrics and Gynecology, University of Verona, 37129 Verona, Italy
4. Department of Diagnostics & Public Health, Specialization School in Health Statistics and Biometry, University of Verona, 37129 Verona, Italy