Depending on the clinical conditions encountered, several extrusion methods can be used. There multiple Mechanical strategies for orthodontic extrusion which allow to control the applied forces. One technique is to place orthodontic cases to the buccal aspect of the adjacent teeth of the tooth to be extruded, in a passive position that does not cause orthodontic movement of the anchoring teeth.
The case applied on the tooth target, is positioned more gingival than the housings of the adjacent teeth. This distance represents the desired orthodontic extrusion by engaging the 0.016” nickel-titanium section wire in the housings. If we hope for more movement, a second, stiffer wire (0.016 “x 0.022”), engaged in enclosures of adjacent teeth only, this serves to stabilize everything. Following extrusion, a wire of section 0.018 in. stiffer stainless steel is inserted and secured with a metal ligation for a minimum period of 12 weeks of detention. If the accessible dental substance is not sufficient for the cementation of a housing, it is possible to carry out the composite reconstruction of the crown or opt for another consolidation strategy. Another consistent strategy for extrusion is to use a rigid wire of 0.7 mm diameter having a hook shape on one of the ends. This wire is cemented into the channel of the tooth to be extruded. It also has elastic which activates the mechanism and needs to be changed every two weeks. This method may be more difficult to achieve on the posterior teeth, because the occlusion could interfere with the mechanism.
If the anchor teeth are free of restoration, a rectangular stainless steel wire of 0.018 or 0.019 in. 0.025″ can be folded and glued using composite to the mouth aspect. Forces must be applied along the long axis of the tooth to be extruded in order to avoid its oral or lingual rocking. A temporary crown cemented on a final pivot can also be used as a traction attachment point while satisfying the aesthetic aspect. If necessary, the contours proximal to the tooth to be extruded must be carefully reduced to avoid interfering with the movement. The number of teeth needed for anchoring depends on the type of the tooth to be extruded, the number and conformation of roots as well as the amount of periodontal attachment. A trace every 2 weeks is recommended to ensure proper oral hygiene and correct any changes in occlusion as the movement progresses. Must also ensure the movement of the treated tooth because, if there is ankylosis, it will move the anchoring complex into intrusion.