OBJECTIVETo assess the value of three-dimensional (3D) reconstruction in treatment planning of impacted teeth.

METHODSThirty-two orthodontic patients with impacted teeth aged from 13 to 17 years were enrolled, including 15 with impacted maxillary canines, 8 with impacted premolars and 6 with second molar impaction and retention. All the impacted teeth were examined by spiral CT scan and 3D reconstruction to determine the 3D position of the tooth in relation to both the crown and root, and the proximity to the roots of other teeth. The data were used for treatment planning and determination of the suitable direction of the orthodontic forces, approaches of surgical exposure, and the position of the attachment to be bonded.

RESULTSNormal occlusion was achieved for 15 patients with transposition maxillary canines and 5 with lower position premolar. Three malformed premolars were extracted after traction. For 9 patients with second molar impaction and retention, normal occlusion was achieved after extraction of the third molar or moving the first molar mesial.

CONCLUSIONSpiral CT scan and 3D reconstruction can accurately determine the 3D position of the impacted tooth and provide assistance in the treatment planning to achieve a higher success rate of orthodontic correction.