Orthodontics is a dynamic and evolving field that requires a deep understanding of both fundamental principles and being abreast with newer advancements. In this digital era, there is an endless access to published literature and books at the disposal of students and professionals. Especially for the student pursuing postgraduation in Orthodontics, shortlisting important and relevant published literature from this vast resource is often a dilema and requires investment of considerable time. This book has been written with the postgraduate students in mind in the form of simplified notes on important topics in orthodontics using an exhaustive reference to the relevant literature. This book will be first of a series, with each book to follow covering several important topics in orthodontics. These notes can be helpful in preparing academic seminars or can be used to brush up important topics at the time of examination. It is hoped that this effort will appeal to all students of orthodontics.