A Creative Spring Design to Force Erupt Labially Impacted Maxillary Canine Using Single Mini Implant

Introduction: Complications to force eruption of impacted teeth may arise from several reasons including ankylosis, dilaceration, and/or some barriers in the eruption pathway. Treatment time prolongation without obvious clinical progress gradually decreases the patient compliance. In this paper we present a non-conventional method to forced eruption of an impacted maxillary canine. Case Presentation: A-۲۱-year old girl presented with missing of teeth No ۱۷, ۱۲, ۲۲, ۲۷, ۳۸, ۳۷, ۴۷, ۴۸ and labially impaction of both maxillary canine was prepared for treatment through apically position flap for exposure of the both canines. Using standard edgewise ۰.۱۸ appliance and conventional elastic traction the right maxillary canine erupted to its normal position after about ۱۸ months but the other tooth had not responded favorably to this technique. There was no signs of ankylosis, a titanium bone screw was placed in the labial cortical bone and mesial of the malposed canine. A spring is made of ۰.۰۱۷” × ۰.۰۲۵” SS wire with two helixes that delivered about ۱۰۰ g force and ۴۰۰ gr.mm activation moment to labial bracket on malposed canine crown. The force exerted on mini implant will be balanced with a force and moment on malposed tooth very similar to type IV Burston classification. After about ۵ months the tooth had reached to its final occlusal position. Conclusions: The appliance used for this patient brought the impacted canine into the arch without any more force on the neighbor teeth. Two point contact of the spring arm by bending the wire over the head of the mini implant made it possible to apply buccolingual crown torque.

Keywords:

Tooth Impacpion , Canine , CBCT , Orthodontic Tooth Movement