“A“ Loop : A New Loop for Management of Impacted or Ectopically Erupted Canines


  • VSPM Dental College and Research Centre, Department of Orthodontic, Nagpur, India
  • Dr. Hazarey’s Dental Clinic and Centre of Excellence for Oral Pre-Cancer, Dental Surgeon, Nagpur, India
  • VSPM Dental College and Research Centre, Department of Orthodontics, Nagpur, India
  • Sharad Pawar Dental College, Department of Orthodontics, India


The ectopic eruption and impaction of permanent canine is a common problem encountered in clinical practice. As maxillary canine is the last permanent tooth to erupt (except third molars), it is most prevalent to be malpositioned or remain impacted due to tooth size arch length discrepancy. The orthodontic treatment of impacted maxillary canine remains a challenge to today's clinicians. The treatment of this clinical entity usually involves surgical exposure of the impacted tooth, followed by orthodontic traction to guide and align it into the dental arch so that it comes into occlusion. Auxiliary springs have been used in orthodontics since long for correction of impacted/unerupted canines or adjacent teeth. Cantilever springs are preferred than the continuous wires as placement of continuous flexible wires for correction of these single tooth malocclusions produces an adverse effect on adjacent teeth. A common disadvantage in all of the loops and techniques mentioned above is that it offers a poor anchorage control in extraction cases. Usually the root of impacted canines is near the cortical bone and needs to be brought into cancellous bone, so as to prevent the resorption and also faster movement of the canine. Keeping these points in mind we designed a loop, which fulfills most of the shortcomings, which are discussed above. This loops is called “A loop†as its shape resembles the shape of alphabet “Aâ€. The design, fabrication, biomechanics, advantages and disadvantages of “A loop†are discussed in this article.


A loop, Ectopically Erupted Canine, Frictionless Mechanics, Impacted Canine, Individual Canine Retraction, Loop Mechanics, Torque Control on Canine

Subject Discipline


Full Text:


Thilander B, Jacobson JO. Local factors in impaction of maxillary canine. Am J Orthod. 1968; 26:145–168.

Cramer HC. Dental survey of one thousand adult males: A Study correlated with physical and laboratory findings. J Am Dent Assoc. 1929;16:122.

Mead SV. Incidence of impacted teeth. Internat J Orthod. 1930; 16:885–190. https://doi.org/10.1016/S0099-6963(30)90010-5

Brin I, Becker A, Shalhav M. Position of maxillary permanent canine in relation to anomalous or missing lateral incisors: A population study. Eur J Orthod. 1986; 8:12–16. https://doi.org/10.1093/ejo/8.1.12. PMid:3456897

Takahama Y, Aiyama Y. Maxillary canine impaction as a possible microform of cleft lip and palate. Eur J Orthod. 1982; 4:275–277. https://doi.org/10.1093/ejo/4.4.275. PMid:6959819

Roher A. Displaced and impacted canines. Int J Orthod Oral Surg. 1929; 15:1003,1020–1024.

Shapira Y, Kuftinec MM. Early diagnosis and interception of potential maxillary canine impaction. J Am Dent Assoc. 1998; 129(10):1450–1454. https://doi.org/10.14219/jada.archive.1998.0080. PMid:9787542

McConnell TL, Hoffman DL, Forbes DP, Janzen EK, Weintraub NH. Maxillary canine impaction in patients with transverse maxillary deficiency. ASDC J Dent Child. 1996; 63(3):190–195. PMid:8853823

Manne R, Gandikota CS, Juvvadi SR, Rama HRM, Anche S. Impacted canines: Etiology, diagnosis, and orthodontic management. J Pharm Bioallied Sci. 2012 Aug; 4(Suppl 2):S234–S238. PMid:23066259 PMCid:PMC3467862

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

Crescini A, Giorgetti R, Cortellini P, Pini Prato GP. Tunnel traction of infraosseous impacted maxillary canines. A three-year periodontal follow-up. Am J Orthod Dentofacial Orthop. 1994; 105:61–72. https://doi.org/10.1016/S08895406(94)70100-8

Darendeliler AM. Treatment of an impacted canine with magnets. J Clin Orthod. 1994; 28:639–643.

Li LCF. Orthodontic traction of impacted canine using magnet: A case report. Cases J. 2008; 1:382. https:// doi.org/10.1186/1757-1626-1-382. PMid:19068138. PMCid:PMC2614941

Becker A. The orthodontic treatment of impacted teeth. 2nd ed. Abingdon, Oxon, England: Informa Healthcare; 2007. p. 1–228.

Kokich VG. Surgical and orthodontic management of impacted maxillary canines. Am J Orthod Dentofacial Orthop. 2004;126:278–283. https://doi.org/10.1016/j.ajodo.2004.06.009. PMid:15356485

Jacoby H. The “ballista spring†system for impacted teeth. Am J Orthod. 1979;75:143–151. https://doi.


Kalra V. The k-9 spring for alignment of impacted canines. J Clin Orthod. 2000; 34:606–610. PMid:11314175

Hauser C. Eruption of impacted canines with an australian helical archwire. J Clin Orthod. 2000; 34:538–541. PMid:11314366

Bowman SJ. The monkey hook: An auxiliary for impacted, rotated, and displaced teeth. J Clin Orthod. 2002; 36:375– 378. PMid:12165978

Bowman SJ, Carano A. The Kilroy spring for impacted teeth. JCO. 2003; 37(12):683–688. PMid:14718742

Park HS, Kwon OW, Sung JH. Micro-implant anchorage for forced eruption of impacted canines. J Clin Orthod. 2004; 38:297–302. PMid:15178885

Vibhute PKJ. Versatile Auxiliary Orthodontic Spring for orthodontic correction of impacted teeth. J of Ind Ortho Soc 2011;45(1): 40–47. https://doi.org/10.5005/ jp-journals-10021-1008

Proffit WR: The biological basis of orthodontic therapy. Contemporary Orthodontics, 4th edition, Proffit WR, Fields HW, Sarver DM, editor. St. Louis: Elsevier; 2007. p. 331–358.

Chay SH, Rabie ABM: Repositioning of the gingival margin by extrusion. Am J Orthod Dentofac Orthop. 2002; 122:95–102. https://doi.org/10.1067/mod.2002.122397. PMid:12142902 25.

Nanda. R: Biomechanics and esthetics strategies in clinical orthodontics. Elsevier Saunders, St. Louis; 2005. p. 201–203.

Halazonetis DJ. Design and test orthodontic loops using your computer. Am J Orthod Dentofacial Orthop. 1997; 111:346– 348. https://doi.org/10.1016/S0889-5406(97)70194-X

Halazonetis DJ. Understanding orthodontic loop preactivation. Am J Orthod Dentofacial Orthop. 1998; 113:237–241. https://doi.org/10.1016/S0889-5406(98)70143-X

Warford Jr JH, Gandhi RK, Tira DE. Prediction of maxillary canine impaction using sector and angular measurement. Am J Orthod Dentofacial Orthop. 2003; 124:651–655. https://doi.org/10.1016/S0889-5406(03)00621-8


  • There are currently no refbacks.