Several Orthodontic appliances, both fixed and removable, have been advocated for the correction of malocclusion caused by sagittal discrepancies between the dental arches and their bony bases. The most frequently reported sagittal malocclusion is skeletal Class II with retrusive mandible, for which a wide variety of treatment modalities have been developed.Many treatment protocols have been put forward for the correction of skeletal class II malocclusion during growth and after completion of growth. Improving a patient's facial profile and correcting the occlusion by positioning the mandible forward is the main objective in correction of a growing skeletal class II malocclusion. Functional orthopedic treatment seeks to correct malocclusions and harmonize the shape of the dental arch and oro-facial function. One main disadvantage of removable functional appliance is patient's compliance, so there evolved noncompliant appliances. This book throws light on various types and uses offixed functional appliances in orthodontics.