This text, now in its second edition, has been rewritten to reflect the changes in the field. Concentrating on the most current concepts and best treatment methods in modern orthodontics, the text provides an overview of diagnosis and treatment planning, followed by step-by-step descriptions of orthodontic techniques. Current information is included on mixed dentition, non-extraction therapy, computerized cephalometrics and the orthodontic aspects of orthogathic surgery. Clinical applications for bio-engineering and physical science principles of orthodontic mechanotherapy are described.