全景片及CBCT对不同前磨牙拔除模式上颌中切牙根吸收的诊断研究

目的　采用全景片及CBCT测量不同前磨牙拔除模式对上中切牙根吸收的影响。方法　正畸患者27例分为3组：T0（不拔牙组）、T1（拔除第一前磨牙组）和T2组（第二前磨牙组），所有患者治疗前后均拍摄全景片和CBCT，对各组上切牙根吸收进行测量。结果　3组患者正畸治疗后均出现不同程度的牙根吸收现象。CBCT测量显示，T1和T2组的中切牙牙根吸收较T0组显著。而T1组的根吸收量大于T2组(P < 0.05)；全景片测量表明，T0组和T2组根吸收差异不显著，T1组的根吸收量大于T0组。CBCT与全景片测量比较，T1和T2组差异无显著性，T0组差异有显著性。结论　不同的拔牙模式会对上切牙的根吸收产生不同的影响。CBCT测量的灵敏度要大于全景片。

Study of effect of different premolar extraction models on the incisor root resorption using panoramic radiography and cone beam computed tomography

Objective　To study the effect of different premolar extraction models on the incisor root resorption using panoramic radiography and cone beam computed tomography，and to provide document for the clinical treatment and diagnosis. .Methods　27 cases were divided into three groups:T0(non-extraction)、T1(extraction of the first premolar) and T2(extraction of the second premolar).Panoramic and CBCT images of all patients were taken immediately before and after treatment.The measurement of the root resorption was performed in the three groups.Results　Root resorption occurred in the three groups.CBCT showed that more significant root resorption occurred in T1 and T2 groups compared with T0 group.And the amount of resorption was more in T1 group than that in T2 group.Panoramic images showed that there was no significant difference in root resorption between T0 and T1 groups. Compared with T0 group,the resorption was more in T1 group.In T1 and T2 groups，no significant difference was found comparing panoramic and CBCT measurement while in T0 group,panoramic and CBCT measurement showed statistical difference.Conclusions　Different premolar extraction models had different effects on the incisor root resorption.The sensitivity of CBCT was better than panoramics.