Jaw modification in Orthodontics is used to correct discrepancies related to maxilla and mandible. The discrepancy can be related to jaw size or position of jaw, resulting in various types of malocclusion including increased overjet or reverse overjet. Jaw discrepancy can be corrected using functional appliances and orthopaedic appliances during growing age, but if growth has been completed, growth modification is not possible. In those cases we need orthognathic surgery to treat skeletal discrepancy. Therefore, it is better to diagnose skeletal discrepancy in early age to treat it using growth modification preventing need of jaw surgery. As normal overjet not only aids in enhancing facial esthetics but also necessary for appropriate functioning. This book will give insight on different treatment options, can be used to treat abnormal overjet.