Читать книгу Orthodontic Treatment of Impacted Teeth - Adrian Becker - Страница 29

In the years prior to the mid‐1960s, a lasso wire (Figure 2.1), twisted tightly around the neck of the canine, was widely employed, and indeed was the type of attachment that we ourselves used in our very earliest cases. It will be readily appreciated that the shape of the crown of a normally shaped healthy tooth is such that its narrowest waist diameter is at the cemento‐enamel junction (CEJ). This is where the lasso wire will inevitably settle. This undesirable consequence will unavoidably result in irritation and recession of the gingival and periodontal tissues and will actively prevent their reattachment in this vital area. There is also evidence that, as a consequence of employing this method, external resorption and ankylosis have been produced in the area of the CEJ [7]. The excellent alternatives that are available today have rendered the lasso wire obsolete.

Fig. 2.1 Lasso wire encircling the neck of an impacted canine (circa 1971).

Fig. 2.2 Threaded pins set into prepared holes, drilled and tapped into the enamel and dentine of the surgically exposed canines (circa 1973).