The Journal of Contemporary Dental Practice
Volume 21 | Issue 12 | Year 2020

Interarch Traction Strategy for Palatal Cuspid Impactions

Adith Venugopal1, Nikhilesh R Vaid2

1Department of Orthodontics, University of Puthisastra, Phnom Penh, Cambodia
2Department of Orthodontics, European University College, Dubai Healthcare City, Dubai, UAE

Corresponding Author: Adith Venugopal, Department of Orthodontics, University of Puthisastra, Phnom Penh, Cambodia, Phone: +85581471447, e-mail:

How to cite this article Venugopal A, Vaid NR. Interarch Traction Strategy for Palatal Cuspid Impactions. J Contemp Dent Pract 2020;21(12):1408–1411.

Source of support: Nil

Conflict of interest: None


Aim and objective: To disimpact a palatally impacted canine using a novel, compliance-dependent technique.

Background: Orthodontic traction of palatally impacted teeth warrants careful mechanical strategies to avoid complications that include root damage to adjacent teeth and resorptions. Sound biomechanical control to avoid these side effects is considered paramount in planning the traction.

Technique: The palatally impacted canine was pulled into the arch with the aid of a modified power arm on the exposed canine and a miniscrew on the lower arch.

Conclusion: The impacted canine was successfully brought into occlusion within 11 months.

Clinical significance: This paper highlights the use of a simple strategy using interarch mechanics and temporary anchorage devices (TADs) to aid in the safe mechanical eruption of impacted palatal canines without the need to bend complex wire designs.

Keywords: Impacted canine, Interarch traction, Miniscrew, Modified power arm.


The maxillary canines are the most frequently impacted teeth except the third molars, with 85% of them lying palatal to the arch.1 There are innumerable approaches to bring palatally impacted canines into the arch. Some of them include the use of Ballista springs,2 Kilroy springs,3 magnets, interarch elastics,4 overlay wires for the traction of such canines,5 and the versatile helical traction mandibular arch (VHTMA).6

Treatment strategies are dictated by various factors including the age of the patient, skill, and expertise of the clinician, anticipated patient compliance, and most importantly anatomical position of the canine (canine crown horizontal overlap with the laterals, the vertical height of the canine crown from the occlusal plane, canine angulation to midline and position of canine root apex horizontally).7

Sound biomechanical planning is necessary to erupt impacted canines without altering the occlusal plane and morphology of adjacent teeth iatrogenically.8 Other deleterious effects of prolonged treatment may involve greater chances of root resorption and loss of vitality of the impacted tooth.9 Literature has definitively also reported higher chances of root resorption of teeth adjacent to the impacted tooth if the mechanical eruption is undertaken.10 This paper highlights the use of a simple strategy using interarch mechanics and temporary anchorage devices (TADs) to aid in the safe mechanical eruption of impacted palatal canines.


A 17-year-old girl complained of non-coincident upper and lower midlines and spaces in her upper front teeth area. She was diagnosed with a mesioangular upper right maxillary canine impaction. A cone-beam computed tomography (CBCT) revealed a complete overlap of the lateral incisors and central incisors, with more than a 30° angulation to the midline and, the apex lying above the roots of the second premolar. The canine crown was placed between both the central incisors and vertically at the apex of their roots (Fig. 1).


The impacted canine was brought into the oral cavity with the help of intermaxillary elastics hooked onto a miniscrew that was inserted in the opposite arch (Fig. 2). As the impacted canine was inaccessible for elastic placement by the patient, an attachment consisting of a lingual button with a long power arm was fabricated, that was then bonded to the exposed surface of the canine.

A small hook was fabricated from an 0.016″ × 0.022″ stainless steel wire, and then wound around a lingual button (Fig. 3A). The flowable composite was added to the open end of the wire to avoid impingement of the wire into the palatal tissues (Fig. 3B). This attachment was then bonded to the exposed surface of the impacted canine (Fig. 4).

A miniscrew (1.6 mm diameter × 8.0 mm length) (Absoanchor, Dentos Inc., Daegu, Korea) was inserted in-between the lower first bicuspid and canine on the side with the impacted canine. The position of the miniscrew may be altered according to the position of the impacted canine on the opposing arch. The miniscrew must be angulated almost perpendicular to the occlusal plane, as an angulated insertion may cause the elastic to disengage more often from the miniscrew head-on activation.

Figs 1A to C: (A) Panoramic image of impacted maxillary canine; (B) Cone-beam computed tomography (CBCT) image of impacted canine (buccal); (C) CBCT image of impacted canine (palatal)

Fig. 2: Biomechanical representation of the technique for traction

Figs 3A and B: (A) A prefabricated hook on 0.016″ × 0.022″ stainless steel wire wound around a lingual button; (B) The flowable composite added to the open end of the wire to avoid impingement of the wire into the palatal tissues

An intermaxillary elastic with small diameter and medium force (1/8″, 4.5 oz) connected the custom attachment on the exposed canine to the miniscrew on the opposing arch (Fig. 5). On activation, the elastic generated a traction force of about 150 g. The patient was asked to wear the elastics throughout the day and change them every 8–12 hours. The elastic wear was discontinued once the canine approximated the base archwire.

Following approximately 11 months of traction, the palatally impacted canine was brought to occlusion (Fig. 6). Some tongue interference and discomfort was reported by the patient during the traction process. This discomfort was reported to be reduced a month into the traction process.

Since it would be easy for food or other debris to get stuck within the attachment, the patient was asked to maintain good oral hygiene, or else there would always be a risk of halitosis or infections.


Untreated impacted canines may lead to cystic lesions around the canine, ankylosis of the canine, recurrent infections, internal resorptions, external resorptions of the canine, and adjacent teeth.11 The sequel of events following external resorption of the adjacent tooth, if left untreated may also lead to tooth loss.12

Fig. 4: Modified power arm bonded to the exposed surface of the canine

Figs 5A and B: A 1/8″ 4.5 oz intermaxillary elastic attached to the miniscrew on the opposing arch: (A) Right buccal view; (B) Frontal view

Figs 6A to C: Impacted right maxillary canine brought to occlusion: (A) Right buccal view; (B) Occlusal view; (C) Panoramic X-ray after bringing the impacted canine into occlusion

Proper diagnosis, timely intervention, and the use of calculated treatment strategies and biomechanics are critical to avoid such complications and correct such challenging malocclusions.

There are innumerable techniques26 that may be used for the traction of such palatally impacted canines. Many of these techniques involve bending wires into complex designs to achieve the biomechanically correct force vectors. They also tend to lacerate the surrounding gingiva causing pain and discomfort to the patient. The abovementioned technique provides for an easy, compliance dependent method to bring down impacted canines.


1. Hitchen AD. The impacted maxillary canine. Br Dent J 1956;100:1–14.

2. Jacoby H. The “ballista spring” system for impacted teeth. Am J Orthod 1979;75(2):143–151. DOI: 10.1016/0002-9416(79)90183-0.

3. Bowman SJ, Carano A. The Kilroy spring for impacted teeth. J Clin Orthod 2003;37(12):683–688.

4. Venugopal A. Interarch traction for impacted canines. APOS Trends Orthod 2020;10(1):60–61. DOI: 10.25259/APOS_133_2019.

5. Fleming PS, Sharma PK, DiBiase AT. How to…mechanically erupt a palatal canine. J Orthod 2010;37(4):262–271. DOI: 10.1179/14653121043200.

6. Vaid NR, Doshi VM, Kulkarni PV, et al. A traction arch for impacted mandibular canines and premolars. J Clin Orthod 2014;48(3):191–195.

7. Counihan K, Al-Awadhi EA, Butler J. Guidelines for the assessment of the impacted maxillary canine. Dent Update 2013;40(9):770–777. DOI: 10.12968/denu.2013.40.9.770.

8. Silva AC, Capistrano A, Almeida-Pedrin RR, et al. Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: A long-term evaluation. J Appl Oral Sci 2017;25(1):75–81. DOI: 10.1590/1678-77572016-0133.

9. Segal GR, Schiffman PH, Tuncay OC. Meta-analysis of the treatment-related factors of external apical root resorption. Orthod Craniofac Res 2004;7(2):71–78. DOI: 10.1111/j.1601-6343.2004.00286.x.

10. Woloshyn H, Artun J, Kennedy DB, et al. Pulpal and periodontal reactions to orthodontic alignment of palatally impacted canines. Angle Orthod 1994;64:257–264.

11. Ahlqwist M, Gröndahl HG. Prevalence of impacted teeth and associated pathology in middle-aged and older swedish women. Community Dent Oral Epidemiol 1991;19(2):116–119. DOI: 10.1111/j.1600-0528.1991.tb00124.x.

12. Guarnieri R, Cavallini C, Vernucci R, et al. Impacted maxillary canines and root resorption of adjacent teeth: A retrospective observational study. Med Oral Patol Oral Cir Bucal 2016;21(6):e743–e750. DOI: 10.4317/medoral.21337.

© The Author(s). 2020 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.