Anterior tooth alignment: A comparison of orthodontic retention regimens 5 years posttreatment

To assess orthodontic treatment outcome at debonding and at 3 and 5 years after orthodontic treatment and to investigate the influence of different retention protocols on anterior tooth alignment.

Using the Peer Assessment Rating (PAR) Index, 169 patients (74 boys, 95 girls) were analyzed at four stages: pretreatment (T0), posttreatment (T1), 3 years posttreatment (T3), and 5 years posttreatment (T5). The PAR anterior component scores (ACSs) were compared between groups with different retention protocols. In the maxilla, protocols were removable retainer until T3 (MAX1), removable and fixed retainer until T3 (MAX2), and removable retainer until T3 and fixed retainer until T5 (MAX3). In the mandible, protocols were no retainer (MAND1), fixed 3-3 retainer until T3 (MAND2), and fixed 3-3 retainer until T5 (MAND3).

Mean weighted improvement in PAR score was 88.3% at T1, 86.4% at T3, and 82.1% at T5. The ACS for the maxilla showed no significant differences between the retention protocols at any time point. In the mandible, the group without retention showed a gradual but not significant deterioration in ACS throughout the posttreatment period. At T5 there was a significant difference in ACS between the group that had the retainer removed at T3 and the group that kept the retainer.

The 5-year treatment outcome, as measured by the PAR Index, was good. Stability of the maxillary anterior alignment 5 years posttreatment did not appear to be influenced by choice of retention protocol. Mandibular anterior alignment was significantly better for the group using a fixed retainer compared with the group where the retainer was removed 3 years posttreatment.