Leveraging the experience of the School of Ferrara, which pioneered aligner treatment in Europe more than twenty years ago, this book is a fascinating journey in the world of aligners. The readers will find a reasoned and evidence-based approach to aligner orthodontic treatment, especially through the use of the F22 aligner. Furthermore, unlike other approaches which are only based on the use of aligners, the book is an introduction to hybrid therapy - a combination of traditional appliances and aligners - for the successful treatment of patients.