"Retention and relapse" was born with the science of Orthodontics and continues to persistently plague Orthodontic researchers and clinicians.Many orthodontists evaluate the retention phase of orthodontic treatment as the most difficult problem of therapy. In fact, the more conscientious the orthodontist, the more he might regard retention as the problem in treatment.Retention is that part of orthodontic treatment during which a passive appliance is used to maintain orthodontic correction of dental and skeletal structures and thereby counteract relapse or the tendency for return of characteristics to original malocclusion