Orthodontics is a branch of dentistry that focuses on the diagnosis, prevention and treatment of jaws and teeth that are malpositioned. Diagnosis and treatment in orthodontics include reorganization of the problem, defining the nature of the problem, designing a treatment based on the needs of the patient and present the treatment strategy to the patient. Diagnosis also includes an in-depth orthodontic assessment of the patient. Orthodontic treatment aims to promote good function and to produce stable results. The majority of orthodontic appliance therapy is done using fixed appliances and removable appliances. Active and functional appliances are the two main types of orthodontic appliances that are commonly used. The objective of this book is to give a general view of the different areas of orthodontics, and its applications. This book covers in detail some existent theories and innovative concepts revolving around this domain. This book is a vital tool for all researching and studying this field.