1. Department of Surgical Sciences, Gnathology Unit, Dental School, University of Torino, Torino, Italy
2. Department of Surgical Sciences, Specialization School of Orthodontics, Dental School, University of Torino, Torino, Italy
3. Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy
4. Department of Medical Sciences, University of Torino, Torino, Italy