Orthodontics and periodontics have a sophisticated elaborate interdependence as every orthodontic intervention has a periodontal extent. Although orthodontic alignment promotes adequate plaque control, many detrimental effects on the periodontium may be observed during the treatment. Periodontal intervention is required at all stages of orthodontic therapy starting from the orthodontist diagnosing a case to a mid-treatment analysis of periodontium and also a posttreatment investigation of the case. Many a time, successful orthodontic treatment is dependent on the overall maintenance of the health of the periodontium. On the other hand, orthodontic tooth alignment may be used as an adjunctive treatment in periodontally compromised patients. This book will help in better understanding the orthodontic-periodontal interrelationship for a better framework of the treatment approach to bring out the optimum results in patients.