Recent studies have indicated
ankylosis, loss of attachment, and external resorption occurring as sequelae of orthodontic movement of
impacted teeth when these teeth are ligated around the cervix with wire. The purpose of this study was to record the effects of two commonly employed methods of attachment to
impacted teeth--the wire
ligation and the direct bond. Twenty subjects who had previously undergone full-banded orthodontic treatment involving a unilateral impacted maxillary canine were studied. The contralateral non-impacted maxillary canine served as a control. In eight of the subjects the impacted canine was ligated at the cervix with wire at the time of surgical exposure. In the other twelve subjects the
impacted tooth also was exposed surgically but then an
orthodontic bracket was bonded directly to the tooth approximately 2 weeks after the surgical exposure. The criterion for the diagnosis of
ankylosis was failure to move the tooth for at least 3 months. The diagnosis of external resorption was made from radiographs. Loss of periodontal attachment was measured by comparing the level of attachment on the previously
impacted tooth with the contralateral canine 3 months after debanding. The results indicated that three of the eight patients in the group receiving wire
ligation exhibited external resorption and
ankylosis. Also, there was an average of 1.36 mm. greater loss of attachment in all four proximal and lingual probing measurements of teeth ligated with
ligature wire but no significant differences in the direct buccal probing measurement.