Three Dimensional Movement Analysis of Maxillary Impacted Canine: a Randomized Clincial Trial

Maxillary canines are the second-most frequently impacted teeth in the dental arch after the third molars. The suspicion of a maxilary canine impaction raises with the absence of the permanent canine in the arch after the normal period of eruption, and has to be confirmed by a clinical evaluation of the patient and a radiographic assessment.

The approaches to the management of impacted canines are many, but the preferred approach typically involves surgical exposure and guided orthodontic eruption.

The initial mechanical eruption can be achieved in several ways, but an important distinction has to be done according to the anchorage method. The aim of this study is comparing Temporary Anchorage Devices (TADs), and cantilevers with a TMA sectional, using the quantification of canines and molars displacement as the main parameter.

A TAD is a mini screw temporarily fixed to bone for the purpose of enhancing orthodontic anchorage either by supporting the reactive unit (the anchoring tooth) or by obviating the need for it at large, and is subsequently removed after use.

The mini screw employed in this clinical trial will be an alloy type IV titanium screw with 1.5mm diameter and 8-10 mm long, and under local anesthesia will be placed in an area between the first premolar and first molar, on the buccal or labial side according to the canine position and teeth position.

For the evaluation of the canines and molar displacement, two CBCT will be required: the first one before the beginning of the traction (T0), the second one after three months (T1). Both the CBCT will be imported in the MIMICS image processing software (Materialize Group, Leuven, Belgium). Limiting the tissue density ranges and restricting the anatomical area of interest, a cropped colored mask will be obtained from each CBCT. Then the co-registration, through the identification of 5 at least landmark points, will allow the overlap of the two masks. At this point, calculating the 3D surface models, the tooth pre- and post-treatment positions will be evident and the measurement of the displacement possible.