Three-dimensional reconstructions of CT scans and cone beam CT of impacted maxillary canines in order to locate areas of ankylosis before orthodontic traction.

PURPOSE

The aim of this study was to model impacted maxillary canines and determine whether areas of ankylosis were present before undertaking orthodontic traction.

MATERIAL AND METHODS

Amira/ResolveRT™ software, version 5.0, by FEI Company is a meshing and surface-rendering program that was used to produce three-dimensional reconstructions from CT scans and cone beam images of the impacted canines of 30 patients (10 cone beam files and 20 CT scan files).

RESULTS AND DISCUSSION

The presence of zones of ankylosis on the roots of certain impacted canines is revealed by the inversion of the direction of meshing on the tooth surface and on a larger scale by invagination of bone tissue into the tooth tissue at various densities measured in Hounsfield units by the AMIRA™ software program. This observation can guide treatment towards extraction of the impacted tooth, its autotransplantation, or deep alveolar corticotomy, followed by mobilization when the canine is in a vestibular position.

CONCLUSION

AMIRA™ software made it possible to detect zones of ankylosis on the roots of certain impacted canines and to adopt a treatment program different from conventional surgico-orthodontic traction. The final aim is to reposition the impacted canine without endangering the adjacent teeth.