CATEGORY AUSTRALASIAN DENTIST 67 LINICAL Light Auxiliary Labial Arch – It is made up of 0.014 inches round SS wire with vertical loops in the area of impacted canine on both sides. This loop has a small helix. This is tied with the basal archwire in piggyback fashion. A vertical and lateral force is being exerted on canine with the auxiliary activated to engage the tooth. If the basal archwire is not used it will lead to extrusion of the adjacent tooth and cause alteration of the occlusal plane. The 0.018-inch stainless steel base archwire minimizes reciprocal effects. Australian helical arch wire – It is made in special plus .016” arch wire and force should not exceed 200 gm. It is activated by twisting the steel ligature wire every two weeks. TMA box loop – A 0.017 X 0.025 TMA wire is used. It produces sagittal and horizontal corrections while continuing vertical eruption. Nickel titanium closed-coil spring – A 0.009”X 0.041” spring. It provides 80 gm of force when stretched to twice its resting length. Easy-Way-Coil (EWC) system – It consists of a Remaniumclosedcoil stainless steel spring, a .010” ligature wire, and a bondable lingual button. Last few coils of the spring were bend to make an eyelet and eyelet was attached to lingual button with a ligature wire. The EWC system allows the constant application of force throughout the eruption of impacted teeth. Mandibular removable appliance – It consists of clasps through which elastic is applied from clasp to the pigtail ligature wire. This provides the necessary extrusive force for the eruption of the canine As mandibular fixed anchorage – A Lingual arch is fabricated with 0.036inch stainless steel wire with vertical hooks (5-6mm in length). Elastic force should not exceed 40-60 gm. Factors taken into consideration in late management u This treatment usually involves fixed appliances and can be time-consuming; therefore, patient motivation and compliance must be high. u The canine must be in a position that makes orthodontic alignment an achievable goal. In particular, those situated as high as the apical third of the incisor roots, beyond the lateral incisor towards the midline or at an angle of greater than 55° to the mid-sagittal plane can be more difficult to align. u Space needs to be available in the maxillary arch for the canine. If this is lacking it will need to be generated, by either distal movement of the buccal segment or extraction. If the lateral incisor is diminutive, some consideration can be given to extracting this tooth; however, first premolars are the usual choice. 2. Autotransplantation Orthodontists should consider treatment alternatives, such as autotransplantation or restoration, in collaboration with other specialists. Autotransplantation involves the surgical removal of an impacted canine and subsequent implantation into its normal positionwithin themaxillary alveolus. Spacewill need tobe available to accept the transplant and a short period of orthodontic treatment may be needed to generate this, particularly if a deciduous canine has been retained. This process will generally be less time-consuming than aligning a canine with orthodontic traction. If the position of the ectopic canine prevents any initial orthodontic treatment, the canine can initially be removed and ‘parked’ under the buccal mucosawhilst the necessary orthodontics is undertaken. Once space has been created for the tooth, a secondary surgical procedure can be undertaken to autotransplant the tooth. Australian helical arch wire Easy-Way-Coil (EWC) system TMA box loop Disadvantages u The teeth can be susceptible to subsequent ankylosis or external root resorption and generally have a reduced long term prognosis in comparison to canines aligned orthodontically. u The technique is highly dependent upon the skill of the surgical operator- Surgical removal of the canine should be as atraumatic as possible to avoid subsequent ankyloses. u The canine should be kept out of occlusion and semi-rigidly splinted for a maximum of three weeks following the transplant. u Once the splint is removed, the canine should be root canal treated to reduce the risk of subsequent external resorption. u Orthodontic movement of transplanted canines is possible but often limited in scope. 3. Replacing a first premolar in the canine position The morphology of the maxillary first premolar differs from that of the canine in several respects: u The root is smaller and often bifid, lacking the characteristic wide and prominent labial surface seen in the canine. u The crown is also smaller from the buccal aspect and there is an additional palatal cusp. From the buccal aspect the premolar crown does resemble that of the canine and this tooth can make an excellent substitute, which can be enhanced by a few modifications: u The premolar root should be placedmore buccally in themaxilla to create a canine eminence. u The crown can also be rotated mesiopalatally which increases the mesiodistal width, helps to hide the palatal cusp and improves the occlusal relation with the mandibular canine. u The palatal cusp can also be ground to reduce its prominence. u Group function in lateral excursion is preferable to guidance, which avoids heavy loading of the less robust premolar root.
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