基于矫治目标的间隙分析法

Space Analysis Based on Treatment Goal(SABTG)

目的探讨基于矫治目标的间隙分析法(Space Analysis Based on Treatment Goal),简称SABTG 间隙分析法,通过在扫描获得的模型影像上完成常规间隙分析三方面的测量,得到综合性拥挤度(Comprehensive Crowding Index,CCI),作为临床矫治设计的参考。方法选取北京大学口腔医院正畸科治疗完成且矫治效果良好病例35例,根据治疗前牙弓形态及尖牙和磨牙问基骨宽度选取最相似的预成弓形再少量调整,形成个体化弓形。依此弓形弯制不锈钢方丝作为进行综合性拥挤度测量的基准曲线。根据治疗前下切牙突度头影测量值和相应治疗后平均值之间的差值,分别确定拔牙和不拔牙治疗后下切牙的位置,将弯制好的方丝固定在模型上进行扫描并测量综合性拥挤度,将所得结果与常规间隙分析法的结果和实际的治疗设计进行比较。结果 SABTG 法中参考治疗后均值确定的下切牙突度变化值更接近实际治疗前后下切牙突度变化值,而常规法中参考正常均值确定的切牙突度变化值与实际变化值之间存在高度显著性差异(P<0.001),表明 SABTG 法能为支抗设计提供更准确的参考。同时,使用 SABTG 法进行分析得到的矫治方案与实际治疗设计的一致率更高,与常规法相比有显著性差异(P<0.05)。结论SABTG 间隙分析法作为一种新的间隙分析方法具有更符合临床实际,可操作性强,测量结果稳定的特点,结果对于临床诊断设计有一定参考作用。

Objective To investigate a new method of space based on Treatment Goal（SABTG）. Comprehensive Crowding Index （CCI） could be achieved from the measurements performed on the scanned model image and the result could be applied to assist clinical treatment planning. Method Thirty-five well- treated cases were chosen. According to the pre-treatment arch form, individual arch form was established and a stainless steel arch wire was made to be used as the standard curve for measurement. Such arch wire was fixed on the model according to correction value of lower incisor protrusion obtained from large-sample analysis. Measurements were performed on scanning images and CCI were achieved respectively. The results were compared with the routine space analysis results and the clinical treatment results. Result Correction value of lower incisor protrusion used in SABTG was closer to the true change value compared with the routine method（P〈0. 001）. It indicated that SABTG could provide more accurate information to anchorage design. Consistency with the clinical treatment results for SABTG in lower dentition was 94. 3%, while that for the routine method was only 77. 1% （P〈0. 05） indicating that statistically significant difference existed between these two methods. Conclusion Space Analysis Based on Treatment Goal （SABTG） was a reliable and practical method to do space analysis. It could be used to assist clinical treatment planning.