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Clinical Pearls
7 (
); 49-51

Canine extrusion with a vertical tube supported cantilever spring

Department of Orthodontics and Dentofacial Orthopedics, KLE Institute of Dental Sciences, Bengaluru, India
Department of Orthodontics and Dentofacial Orthopedics, Maratha Mandal’s Nathajirao G Halgekar Institute of Dental Sciences and Research Centre, Belgaum, Karnataka, India
Address for Correspondence: Dr. U. H. Vijayashree, Department of Orthodontics and Dentofacial Orthopedics, KLE Institute of Dental Sciences, Bengaluru - 560 022, Karnataka, India. E-mail:
This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 3.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.
This article was originally published by Wolters Kluwer and was migrated to Scientific Scholar after the change of Publisher; therefore Scientific Scholar has no control over the quality or content of this article.

How to cite this article: Vijayashree UH, Pai V. Canine extrusion with a vertical tube supported cantilever spring. APOS Trends Orthod 2017;7:49-51.


Maxillary canine is the most frequently impacted tooth in the dental arch and twice common in females than in males. Treatment of impacted maxillary canine can be difficult and time consuming, depending on its position. Improper direction and magnitude of applied force can lead to increased chances of adjacent tooth resorption. This article describes about a simple cantilever spring that can be fabricated at chair side for extrusion of a bucally impacted canine.


Canine extrusion
cantilever spring
vertical tube


A buccally impacted canine is most commonly encountered and is usually positioned near the root of an adjacent tooth and mesial to its normal position [Figure 1].[1] One of the challenges of such vertical tooth movement is prevention of unwanted side effects on the molar.

Figure 1: Pretreatment intraoral left lateral photograph

Cantilever springs are simple and efficient orthodontic appliances, with a wide variety of clinical uses. Biomechanically, cantilevers are able to produce statically determinant force systems, giving the clinician the opportunity to deliver qualitatively and quantitatively precise forces.[2] A cantilever spring consists of 2 arms, the fixed and free end. The fixed end is inserted into a bracket or a tube, and the free end applies a point contact and does not engage a bracket slot or tube.

A 0.019” × 0.025” stainless steel archwire was placed in the maxillary arch, and a vertical tube was soldered to it between the premolars [Figure 2]. A 0.017” × 0.025” titanium-molybdenum alloy cantilever spring of 3 mm helix was fabricated with two arms [Figure 3]. The vertical arm, i.e., the fixed end of cantilever spring, was inserted into the soldered vertical tube and cinched [Figure 4], and the horizontal arm which is at 90° to the vertical arm was activated to in the incisal direction by closing the helix and forcefully engaging into the bracket bonded on the impacted canine [Figures 4 and 5]. This cantilever spring exerted 50 g of force for canine extrusion as measured with a force gauge [Figures 6 and 7].

Figure 2: 0.019” × 0.025” Stainless steel wire with soldered vertical tube
Figure 3: 0.017” × 0.025” Titanium-molybdenum alloy cantilever spring (passive)
Figure 4: Cantilever spring activation for canine extrusion
Figure 5: The vertical arm of the cantilever spring cinched
Figure 6: Progress of canine extrusion over 2 months
Figure 7: Canine extrusion after 6 months of cantilever mechanics

This spring was shown to be an effective means of aligning buccally impacted maxillary canines [Figures 4 and 5]. Final alignment and leveling of canine was performed using 0.019” × 0.025” stainless steel wire. The residual space closure was done using active tie backs [Figure 8]. Post treatment intraoral photograph showing well aligned maxillary canine in the arch [Figure 9].

Figure 8: Space closure with stainless steel base archwire after canine alignment
Figure 9: Posttreatment intraoral left lateral photograph

This spring can be easily fabricated and activated at chair side for extrusion of a single tooth to avoid the unwanted effects on the molar and can also be used when an auxiliary molar tube is not available.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


  1. , , . A cantilever spring for alignment of buccally impacted canines. J Clin Orthod. 2012;46:354-5.
    [Google Scholar]
  2. . Cantilever springs: Force system and clinical applications. Semin Orthod. 2001;7:150-9.
    [Google Scholar]

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