A thorough knowledge of the biochemical mediators of orthodontic tooth movement and their mechanisms will provide a rational for better and effective orthodontic treatment.Therefore an effort is made through this book titled "Chemical mediators in orthodontic tooth movement" to provide an opportunity for the reader to understand and update the knowledge on the latest research on biological changes occurring at the molecular level. This would in turn help an orthodontist in delivering better mechanics, producing quicker tooth movement with minimum tissue damage and maximum comfort to the patient.