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.