A healthy periodontium is one of the key to successful orthodontic treatment. In the present era, a significant number of patients seeking orthodontic treatment are adults and hence importance of multidisciplinary treatment cannot be ruled out. As orthodontists enter the 21st century, adoption of evidence based health care and invention of new preventive strategies are primary goals. The most commonly argued rationale for this treatment is that dental alignment obtained with orthodontic therapy facilitates plaque removal and reduces occlusal trauma. This book covers starting from the basics of anatomy of periodontium and biology of tooth movement to the latest advances that have been made to accelerate the tooth movement , treatment for periodontally compromised patients and much more. Orthodontic-periodontic interactions are mutually beneficial. The combined approach can greatly enhance the periodontal health and dentofacial aesthetics.