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Orthodontic extrusion for a preprosthetic approach: a bracketless mini-implant-based mechanics.

AIM
To propose a new mini-implant-based mechanics for the orthodontic extrusion of fractured posterior teeth.


METHODS
An innovative biomechanical bracketless system was used to gain vertical movement of fractured maxillary molars with three-dimensional control to meet preprosthetic objectives. Two slotted-head mini-implants were inserted between the roots of the canine and premolars. A sectional TMA wire was passively adapted to the mini-implant positions and connected to the first molar by a crossing crown hole. The extrusion movement was achieved in two phases. In the first phase, a vertical spring loop was formed in the sectional wire for initial pure vertical movement. Next, a horizontal spring loop was modeled to improve the proper spatial position of the molar.


CONCLUSION
The extrusion movement and stabilization were achieved without patient compliance. The maxillary molar was extruded about 3 mm, allowing exposure of the most apical border of the fracture, giving the prosthodontist the proper clinical conditions for ideal restoration of the tooth.