Boyd R L
Am J Orthod. 1982 Dec;82(6):478-86. doi: 10.1016/0002-9416(82)90316-5.
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.
近期研究表明，当阻生牙在颈部用金属丝结扎进行正畸移动时，会出现关节强直、附着丧失和外部吸收等后遗症。本研究的目的是记录两种常用的阻生牙附着方法——金属丝结扎和直接粘结的效果。对20名先前接受过涉及单侧上颌阻生尖牙的全带环正畸治疗的受试者进行了研究。对侧未阻生的上颌尖牙作为对照。在8名受试者中，阻生尖牙在手术暴露时在颈部用金属丝结扎。在其他12名受试者中，阻生牙也进行了手术暴露，但在手术暴露后约2周，正畸托槽直接粘结到牙齿上。关节强直的诊断标准是牙齿至少3个月未移动。外部吸收的诊断通过X线片进行。在拆除带环3个月后，通过比较先前阻生牙与对侧尖牙的附着水平来测量牙周附着丧失。结果表明，接受金属丝结扎的8名患者中有3名出现了外部吸收和关节强直。此外，用结扎丝结扎的牙齿在所有四个近中及舌侧探诊测量中平均附着丧失多1.36毫米，但在直接颊侧探诊测量中无显著差异。
