CATEGORY 66 AUSTRALASIAN DENTIST LINICAL position. The problem of long clinical crown or loss of attachment is less with this technique. Kokich (AJO 2004) reported three methods for uncovering a labially impacted maxillary canine: gingivectomy, creating an apically positioned flap, and using closed eruption techniques If the crown is located below themucogingival junction, an open procedure is appropriate and the crown simply uncovered. For canines above the mucogingival junction, a closed exposure and bonding with gold chain is the treatment of choice unless the canine is labial to the lateral incisor; then an apically repositioned flap will provide the best chance of the tooth erupting through an attached gingiva. Palatal impaction Themost commonmethods used tobringpalatally impacted canines into occlusion are surgically exposing the teeth and allowing them to erupt naturally during early or late mixed dentition and surgically exposing the teeth and placing a bonded attachment to and using orthodontic forces to move the tooth. For palatally impacted canines an open or closed technique can be used, depending on the position of the tooth. The flap design is less critical in a palatally impacted tooth. Using fixed appliances, traction can be applied with flexible piggyback archwires, elastomeric chain or string, rigid buccal arms or even magnets. After adequate moisture control, bonding is completed and the flap is closed. The orthodontist should attach the ligature wire to the palatal arch or any other spring is used for eruption. The most efficient way for impacted canines to erupt is to use closed-coil springs with eyelets. Traction force is applied immediately as later manipulation is painful to the patient. The tooth usually erupts in 2–3 visits. The choice of technique will depend largely upon canine position and preference of the orthodontic operator. Various methods of attachment Placement of wire ligature around the neck of the tooth results in loss of periodontal attachment, because the bone destroyed does not regenerate when the wire is removed. This method is not preferable. Rarely a hole is prepared in the crown of the exposed tooth and a pin or wire inserted into it. This is connected to the main archwire. Chances for non-vitality of the tooth can occur. The best approach is to expose the crown and directly bond an attachment to the exposed surface. Bonded attachments can be hooks, buttons, brackets or chains. Auxiliary springs for canine movement: Ballista Spring – It is made of rectangular wires. It proceeds forward until it is more opposite to canine space and bent vertically downwards and terminate into a small loop. With slight finger pressure, spring is tied to the pigtail ligature, by this it provides an extrusive force for the canine to erupt. If the impacted tooth is resistant tomovement or if the distance for the tooth tomove is more it will lead to lingual molar root torque leads to loss of anchorage. To overcome this feature TPA is advised. Other vairation of ballista spring/loops with SS round wire can also be custommade. K-9 spring – It is made in 0.017”X 0.025”TMA wire. It is simple in design and exerts light continuous eruptive and distalizing forces. Active palatal arch – It consists of a fine 0.020-inch removable palatal arch wire carrying an omega loop on each side. The end of the wire is doubled for frictionless fit in lingual sheath. It is activated by elevating downward activated palatal archwire and hooking the pigtail ligature around it. Kilroy Spring – Delivers a constant force module that is slid onto a rectangular archwire over the site of an impacted tooth. In the passive state, the vertical loop of the Kilroy Spring extends perpendicularly from the occlusal plane. To activate the spring, a stainless steel ligature is guided through the helix at the apex of the vertical loop, and the loop is directed toward the impacted tooth.The ligature is then tied to an attachment that has been direct-bonded to the surgically exposed tooth. A ‘piggy back’ flexible wire has been deflected in order to apply traction to the gold chain which has been applied to the palatally positioned canine. Stiff wire base to prevent unwanted reactions to traction. Ballista Spring K-9 Spring Active palatal arch Kilroy spring Light auxiliary labial arch
RkJQdWJsaXNoZXIy MTc3NDk3Mw==