Statement of problem

Research on the quantification of 3-dimensional tooth movements in patients undergoing treatment using the Dahl principle is lacking.

Purpose

The purpose of this observational clinical study was to measure the magnitude, direction, duration, and rate of tooth movement occurring in patients to reestablish tooth contact and create restorative space.

Material and methods

A total of 104 paired preoperative and postoperative physical and virtual casts from 26 patients were obtained. Commencement and completion dates were recorded to calculate movement duration to reestablish occlusion. Dental casts were digitized, and the 3-dimensional digital casts obtained were superimposed via a surface matching and analysis software program by using the global registration function. Color maps were used to visualize direction, and the annotation feature quantified magnitude of tooth movement in millimeters when specific reference points were selected. Teeth within the arch were categorized as per their location to evaluate their impact on occlusal reestablishment. The average rate of movement was determined by time taken for extrusive and intrusive movements over the treatment duration. Post hoc Tukey tests were applied if a significant difference was present in the magnitude of movement between different tooth categories.

Results

All participants showed evidence of tooth movement during treatment. Duration of occlusal reestablishment ranged from 3.9 to 28.2 months, with more posterior tooth extrusive movements (56.9%) than anterior tooth intrusive (43.1%) movements occurring. A comparison of magnitude of extrusive or intrusive movement between categories (molar-anterior, premolar-anterior, and premolar-molar) showed that premolar and molar extrusive movements and anterior intrusive movements were significantly different (P<.001). The amount of buccal and lingual movement for molars and premolars was similar. Anterior teeth demonstrated more buccal than lingual movements. All teeth showed more mesial than distal movements. The extrusive and intrusive movement rate was 0.13 and 0.11 mm/mo, respectively.

Conclusions

Tooth movement occurred in patients regardless of age and sex. The results of this study indicated that tooth movements have a 3-dimensional nature. Occlusal reestablishment mainly occurred via a combination of extrusive and intrusive movements. The study further highlighted the advantages of digital technology such as surface scanners and 3-dimensional software programs that can be used to quantify change in patients undergoing treatment.

中文翻译：

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使用 Dahl 原理测量牙齿移动：一项观察性研究

问题陈述

缺乏使用 Dahl 原理对接受治疗的患者进行 3 维牙齿移动量化的研究。

目的

这项观察性临床研究的目的是测量患者牙齿移动的幅度、方向、持续时间和速度，以重新建立牙齿接触并创造修复空间。

材料与方法

总共获得了来自 26 名患者的 104 个配对的术前和术后物理和虚拟模型。记录开始和完成日期以计算运动持续时间以重建咬合。牙科模型被数字化，获得的 3 维数字模型通过表面匹配和分析软件程序使用全局配准功能叠加。Color maps were used to visualize direction, and the annotation feature quantified magnitude of tooth movement in millimeters when specific reference points were selected. 根据位置对牙弓内的牙齿进行分类，以评估它们对咬合重建的影响。平均运动速率由治疗期间进行挤压和侵入运动所花费的时间确定。

结果

所有参与者在治疗期间均表现出牙齿移动的迹象。咬合重建的持续时间为 3.9 至 28.2 个月，发生的后牙突出运动 (56.9%) 多于前牙侵入运动 (43.1%)。比较类别（磨牙-前牙、前磨牙-前牙和前磨牙-磨牙）之间的挤压或侵入运动的幅度表明，前磨牙和磨牙的挤压运动和前牙侵入运动有显着差异（P <.001）。臼齿和前臼齿的颊舌运动量相似。前牙表现出更多的颊运动而不是舌运动。所有牙齿都显示出比远中运动更多的近中运动。挤出和侵入运动速率分别为 0.13 和 0.11 毫米/月。

结论

无论年龄和性别，患者都会发生牙齿移动。这项研究的结果表明，牙齿移动具有 3 维性质。咬合重建主要通过挤压和侵入运动的组合发生。该研究进一步强调了表面扫描仪和 3 维软件程序等数字技术的优势，这些技术可用于量化接受治疗的患者的变化。