研究微创正畸牵引复位无自发萌出能力的外伤挫入年轻恒牙的临床疗效。

选择年轻恒牙外伤挫入的患者8例，年龄7~ 11岁，共11颗上颌切牙，其中9颗重度挫入、2颗中度挫入。观察1个月以上，确定无自发萌出能力后，采用如下微创正畸牵引方式复位：（1）"2 × 4"镍钛弓丝技术：单颗牙中度挫入，邻牙萌出3/4以上；（2）活动基托牵引：重度根向挫入、邻牙萌出不足1/2或伴脱位性损伤；（3）活动基托牵引联合"2 × 4"镍钛弓丝技术：重度唇向或腭向挫入，邻牙萌出不足1/2或伴脱位性损伤。观察治疗后患牙萌出状况、牙根吸收、边缘骨缺损和（或）牙髓变化情况。

（1）患牙萌出状况：所有挫入牙均复位；（2）牙根吸收情况：4颗牙出现轻微根吸收，2颗牙牵引前出现根尖部和根中段侧方低密度影，治疗完成时低密度影消退，余牙均无牙根吸收；（3）边缘骨缺损情况：除2颗牙外均无边缘骨缺损；（4）牙髓活力状况：3颗牙齿发育Nolla 10期的挫入牙，牵引前即行牙髓摘除术，4颗牵引中行牙髓摘除术，4颗牙髓活力正常，其中1颗根管钙化。

无萌出潜力的挫入年轻恒牙可根据其挫入方向及邻牙萌出程度和受伤情况，分别选择"2 × 4"镍钛弓丝技术、活动基托牵引技术或活动基托联合"2 × 4"镍钛弓丝牵引技术，及时进行微创牵引，可有效复位挫入牙，避免牙根吸收，减少边缘骨缺损，并可能保存活髓，值得进一步推广。

To observe the clinical outcomes of traumatically intruded young permanent teeth after using a minimal invasive orthodontic repositioning method.

Eight patients aged from 7 to 11 years old presenting dental trauma were admitted to our department. A total of 11 injured maxillary incisors, with 9 severely intruded and 2 moderately intruded. All teeth were observed for spontaneous re-eruption for at least 1 month, before initiating orthodontic repositioning. Minimal invasive orthodontic repositioning were possible using the following method: (1) "2 × 4" nickel titanium wire appliance: single tooth moderately intruded with adjacent teeth erupted above 3/4; (2) removable appliance: severely and vertically intruded tooth, with adjacent teeth erupted less than 1/2 or traumatically dislocated; (3) removable appliance and "2 × 4" nickel titanium wire appliance: severely buccal or palatal intruded tooth, with adjacent teeth erupted less than 1/2 or traumatically dislocated. During the re-eruption status, pulp necrosis, loss of gingival attachment, marginal bone loss, root resorption and the condition of adjacent teeth were observed.

(1) Re-eruption status: all the teeth were repositioned in good alignment with the adjacent teeth; (2) root resorption: 4 teeth showed mild root resorption. 2 teeth showed evidence of obvious periapical and lateral radiolucency before the repositioning, which were ceased and healed at the end of the treatment; (3) marginal bone loss: 2 teeth showed mild marginal bone loss; (4) pulp status: 3 mature teeth were root-treated with calcium hydroxide paste before the repositioning, 4 immature teeth were treated during the treatment, and 4 teeth maintained pulp vitality, one tooth showed root canal calcification.

If the traumatically intruded teeth show no signs of re-eruption, depending on the direction of intrusion, the stage of eruption of the adjacent teeth and the severity of the trauma, immediate repositioning should be initiate. "2 × 4" nickel titanium wire appliance, removable appliance or even the use of both in one unit should be a feasible choice to effectively reposition dislocated tooth, avoid root absorption, reduce the occurrence of marginal bone loss, and maintained pulp vitality.