减数拔牙后正畸治疗中断情况下牙齿漂移的研究

Study of tooth drifts after orthodontic extractions in cases of interruption

目的比较不同类型患者减数拔牙后正畸治疗中断1.5月(45 d)后牙齿漂移的程度。方法本研究已通过单位伦理委员会审查批准,并获得患者知情同意。选取已拔双侧前磨牙但因故未按时进行粘接托槽治疗的84例患者为研究对象。对患者的口腔上下颌模型进行三维扫描、重建和测量,根据患者的拔牙牙位(第一前磨牙或第二前磨牙)、颌骨类型(上颌或下颌)、垂直骨面型(均角、高角或低角)将其分为12组,应用多因素方差分析减数拔牙之后治疗中断1.5月情况下以下5项指标的变化,包括前牙拥挤度、尖牙间宽度、磨牙间宽度、拔牙间隙、前牙覆。结果拔牙牙位、颌骨类型、垂直骨面型对减数拔牙后1.5个月拔牙间隙的减小量、前牙拥挤度的减小量有影响(P<0.001),拔牙牙位和垂直骨面型对前牙覆增加量有影响(P<0.001)。拔除第一前磨牙的患者相对于拔除第二前磨牙的患者双侧邻牙的漂移明显(P<0.001),上颌双侧邻牙漂移较下颌明显(P<0.001),高角的患者较均角及低角的患者双侧邻牙漂移量明显(P<0.001)。结论对于正畸患者,如果存在上颌减数、第一前磨牙减数、垂直骨面型为高角的情况,拔牙双侧邻牙容易漂移,应该在减数拔牙后及时正畸治疗,并且注意支抗的控制。

Objective To compare the tooth drift differences between different types of patients after orthodontic extraction for 1.5 months(45 days)without return to the clinic on time for some reasons.Methods This study has been reviewed and approved by the Ethics Committee,and informed consent has been obtained from patients.A total of 84 patients had bilateral premolars extracted but were not bonded the bracket for some reasons.The upper and lower jaw dental models were cast,scanned,and reconstructed in 3D.Patients were divided into 12 groups based on extraction positions(first premolar or second premolar),jaw types(maxilla or mandible)and vertical facial types(average angle,high angle,or low angle).Multivariate analysis of variance was used to analyze the changes in the following five indicators in different types of patients who were interrupted for 1.5 months after extraction:anterior tooth crowding,width between canines,width between first molars,tooth extraction space,and overbite of anterior teeth.Results The tooth extraction position,jaw type and vertical facial type had an effect on the reduction in tooth extraction space and anterior tooth crowding before and after the sudden emergent state(1.5 months after tooth extraction)(P<0.001),and the tooth extraction position and vertical facial type had an effect on the increase in anterior tooth overbite(P<0.001).The drift of bilateral adjacent teeth was greater in patients with first premolars extracted than in those with second premolars extracted(P<0.001),and the drift of bilateral adjacent teeth in the maxilla was larger than that of the mandible(P<0.001).The drift of bilateral adjacent teeth in patients with high angles was more obvious than that of patients with average angles and low angles(P<0.001).Conclusion For orthodontic patients who have maxillary tooth extraction,first premolar extraction,and even high angles in the vertical facial type,the bilateral adjacent teeth are easier to drift,orthodontic treatment should be carried out soon after extraction,and attention should be given to anchorage control.