Abstract
Research into the long-term stability of orthodontic treatment at the University of Nijmegen (the Netherlands) until 10 years after retention has shown that nearly 50% of the total relapse takes place the first two years after retention. After that period certain stability is reached except for the lower front teeth. Ten years after the retention phase their position is even worse than at the start of treatment. The changes in lower front teeth alignment are the result of relapse, but also of normal physiological changes during ageing of the dentition. Therefore it is questionable whether late mandibular incisor irregularity should be (re)treated. Relapse of mandibular incisor alignment shortly after debonding can be restored by tightly tying the rotated incisor(s) to the C-C bar with a steel ligature, by using a spring-retainer or by rebonding of brackets to the lower front teeth. After correction of the incisor position the C-C bar should be bonded to all lower front teeth. (Re)treatment of mandibular incisor irregularity at an older age asks for more complicated treatment mechanics.
