评价隐形矫治不同阶段数字化模型牙齿宽度值测量可重复性，以探讨临床是否可以据此进行邻面去釉（IPR）完成量的评估。

纳入不拔牙隐适美矫治患者50例，治疗中未进行IPR。治疗前（T1）及治疗后（T2，第一次中途重启或精调时）的数字化牙颌模型均由隐适美iTero口内扫描获得。ClinCheck软件中显示了分割后单颗牙齿宽度及根据Bolton指数（前牙比和全牙比）所显示的牙量不调值，计算上下颌前牙段牙齿宽度之和（UATW和LATW）、上下颌全牙段牙齿宽度之和（UOTW和LOTW）。利用组内相关系数（ICC）评价T1、T2时间点牙齿宽度数据的可重复性，利用两时间点的差值评价牙齿宽度的精度。将患者分别按拥挤度、性别和年龄进行分组，比较不同组间牙齿宽度精度的差异。

牙齿宽度值ICC均≥0.917。单颗牙齿宽度两次差值的均值为-0.09 ~ 0.03 mm，标准差为0.06 ~ 0.17 mm。UATW、LATW、UOTW和LOTW两次测量差值的均值为-0.14 ~ 0.10 mm，标准差为0.21 ~ 0.53 mm。Bolton分析前牙比差值为（0.02 ± 0.71）%，全牙比差值为（0.25 ± 0.61）%。间隙组LOTW两次测量差值较大，与不拥挤组和拥挤组比较差异有统计学意义（P<0.05），不同性别和年龄组牙齿宽度精度差异均无统计学意义（P>0.05）。

ClinCheck软件中隐形矫治不同阶段数字化模型牙齿宽度测量数据可重复性高，测量精度在临床可接受范围，但个体宽度数据变异较大。年龄和性别对牙齿宽度精度无影响，牙列拥挤度有一定影响。临床一定程度上可以参考分割后的牙齿宽度进行方案设计和IPR完成量评价。

To explore the reproducibility of tooth width measurements in digital models from different stages of Invisalign^? treatment, and provide evidence for evaluation of the achieved amount of interproximal reduction (IPR) .

Fifty nonextraction patients were treated with Invisalign^? without interproximal reduction. Digital models of each patient were acquired using the iTero intraoral scanner and examined using ClinCheck software twice: at the start of the case (T1) and during the first midcourse correction or refinement (T2) . The individual tooth width and the anterior and overall Bolton ratios were recorded from ClinCheck. The upper and lower combined anterior and overall teeth widths (UATW, UOTW, LATW and LOTW respectively) were calculated. The reproducibility was determined using intraclass correlation coefficients (ICCs) . The differences between T1 and T2 were used to assess the precision of tooth width. The cases were further divided into groups according to tooth arrangement, age and sex, and the precision of combined teeth width measurements among groups were compared.

The individual tooth width, combined teeth widths and Bolton ratios had ICCs≥0.917. For individual tooth width, the mean differences between T1 and T2 were-0.09-0.03 mm, and the standard deviations were 0.06-0.17 mm. For combined teeth widths, the mean differences were-0.14-0.10 mm, and the standard deviations were 0.21-0.53 mm. The difference in anterior ratio was (0.02 ± 0.71) % and in overall ratio was (0.25 ± 0.61) %. The precision of LOTW showed significant difference among the Spacing, Non-crowding and crowding groups (P<0.05) , while the precision of UATW, UOTW and LATW showed no significant difference (P>0.05) . The precision of all four combined teeth widths measurements showed no significant difference between female and male groups (P>0.05) or between adolescent and adult groups (P>0.05) .

The individual tooth width and combined teeth widths measurements of the digital models from different stages of Invisalign^? treatment showed high reproducibility and clinically acceptable precision in ClinCheck. However, the precision had a relatively large individual variability. The precision of combined teeth widths were not influenced by age and sex but by tooth arrangement to some extent. The tooth width measurements could be generally used as reference for treatment plan and evaluation of the achieved IPR amount.