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

Abstract

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 "A”. The design, fabrication, biomechanics, advantages and disadvantages of "A loop” are discussed in this article.