Clinical effect of a door shaped individualized dental archwire on the treatment of maxillary transposed canines

Objective To discuss the effectiveness and mechanism for movement of maxillary buccally transposed canines by using a door-shaped individualized dental archwire mechanic and to provide a reference for clinicians. Methods Eight patients with unilateral maxillary transposed canines were enrolled. All patients were treated with door-shaped individualized archwires. Before treatment (T1) and after the crowns of the transposed canines were moved to the right buccal positions in the dental arch during the treatment (T2), orthopantomograms were taken both at T1 and T2 to compare the linear changes (distance changes of the crown and root apex) and angular changes to study the mechanisms of tooth movement. The probing depth and buccal crown height were measured using a periodontal probe to compare periodontal changes before treatment (T1) and after treatment (T3) between the transposed canines and contralateral canines. Results All eight transposed canines were successfully brought back to their normal dental arch position but were made more buccal by using the door-shaped individualized dental archwire, with a mean of (11.5 ± 2.7) months. The average overall duration was (28.3 ± 4.7) months. The crown distance changes of the canines from T1 to T2 (8.1 mm) were greater than those of the root apexes (1.5 mm) (P0.05). Conclusion The buccal movement of maxillary transposed canines under a door-shaped individualized dental archwire was effective and feasible. The movement pattern under this mechanism was controlled tipping.