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Case Reports
. 2017:2017:7275846.
doi: 10.1155/2017/7275846. Epub 2017 May 14.

Asymmetric Expansion with a Modified Quad Helix for Treatment of Isolated Crossbite

Marisabel Magnifico  1 , Alberto Di Blasio  1 , Diana Cassi  1 , Chiara Di Blasio  2 , Mauro Gandolfini  1
Affiliations
Case Reports

Asymmetric Expansion with a Modified Quad Helix for Treatment of Isolated Crossbite

Marisabel Magnifico et al. Case Rep Dent. 2017.

Abstract

Unilateral posterior crossbite often involves only one tooth, especially upper first molar; in these cases it is never easy to obtain an asymmetrical movement of a molar and a proper planning of the orthodontic device with its anchorage is necessary to avoid arch overexpansion. Thanks to its simplicity and efficacy, the modified Quad Helix here described represents a valid therapeutic tool in cases of isolated posterior crossbite.

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Figures

Figure 1
Figure 1
Patient with crossbite of upper left first permanent molar.
Figure 2
Figure 2
A single force applied to the bracket (not through the center of resistance) will cause rotation of the tooth.
Figure 3
Figure 3
Moment (M) produced by a force not acting through Cres.
Figure 4
Figure 4
Asymmetric Quad Helix (left) and traditional Quad Helix (right).
Figure 5
Figure 5
Details of the single terminal (a) and the terminal introduced together with the wire segment of the same diameter into the Goshgarian tube and welded to the band (b).
Figure 6
Figure 6
Asymmetric Quad Helix: extraoral (a) and intraoral (b) views. When the auxiliary wire segment is applied into the mouth, it must not interfere either with the mucosa or with the band in order to not give rise to undesired positions or stress.
Figure 7
Figure 7
Application and activation system of the asymmetric Quad Helix; it can be seen that there is the absence of a torque control allowing the expression of a single force on tooth 2.6.
Figure 8
Figure 8
Rapid resolution of crossbite of tooth 2.6.
See this image and copyright information in PMC

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