Wire Syndrome (WS) is an iatrogenic complication of fixed orthodontic retention, characterized by progressive and unexpected tooth movements despite the presence of an apparently intact retainer. These movements cannot be attributed to physiological orthodontic relapse. Although the literature has reported numerous cases associated with periodontal damage and aesthetic and functional impairment, the biomechanical mechanisms underlying this syndrome remain controversial. This presentation illustrates the two main clinical patterns: the X-effect and the Twist-effect. The X-effect is characterized by an abnormal expression of root torque, whereas the Twist-effect is associated with torsional deformation of the retainer–tooth complex. A unifying interpretation is proposed, according to which both patterns represent different manifestations of a loss of biomechanical passivity within the retention system. This concept has important implications for the early diagnosis, prevention, and clinical management of Wire Syndrome.