Purpose

A dental splint was developed for non-invasive rigid point-based registration in electromagnetically (EM) navigated mandibular surgery. Navigational accuracies of the dental splint were compared with the common approach, that is, using screws as landmarks.

Methods

A dental splint that includes reference registration notches was 3D printed. Different sets of three points were used for rigid point-based registration on a mandibular phantom: notches on the dental splint only, screws on the mandible, contralateral screws (the side of the mandible where the sensor is not fixated) and a combination of screws on the mandible and notches on the dental splint. The accuracy of each registration method was calculated using 45 notches at one side of the mandible and expressed as the target registration error (TRE).

Results

Average TREs of 0.83 mm (range 0.7–1.39 mm), 1.28 mm (1.03–1.7 mm), 2.62 mm (1.91–4.0 mm), and 1.34 mm (1.30–1.39 mm) were found, respectively, for point-based registration based on the splint only, screws on the mandible, screws on the contralateral side only, and screws combined with the splint.

Conclusion

For dentate patients, rigid point-based registration performs best utilizing a dental splint with notches. The dental splint is easy to implement in the surgical, and navigational, workflow, and the notches can be pinpointed and designated on the CT scan with high accuracy. For edentate patients, screws can be used for rigid point-based registration. However, a new design of the screws is recommended to improve the accuracy of designation on the CT scan.

中文翻译：

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利用3D打印的牙夹板​​在下颌电磁导航手术中进行配准

目的

开发了一种牙夹板，用于在电磁（EM）导航的下颌手术中进行非侵入式基于刚性点的配准。将牙夹板的导航精度与常用方法（即使用螺钉作为界标）进行了比较。

方法

3D打印了包含参考配准槽口的牙科夹板。使用三组不同的点对下颌模型进行基于刚性点的配准：仅在牙齿夹板上开槽，在下颌骨上固定螺钉，对侧螺钉（下颌骨未固定传感器的一侧）以及螺钉组合在下颌骨上和在牙齿夹板上的缺口。使用下颌骨一侧的45个凹口计算每种配准方法的准确性，并表示为目标配准误差（TRE）。

结果

对于基于点的配准，平均TRE分别为0.83毫米（0.7-1.39毫米），1.28毫米（1.03-1.7毫米），2.62毫米（1.91-4.0毫米）和1.34毫米（1.30-1.39毫米）。仅基于夹板，下颌骨螺钉，仅对侧螺钉以及与夹板结合的螺钉。

结论

对于有牙齿的患者，基于刚性点的配准最好使用带有缺口的牙科夹板。牙夹板很容易在外科和导航工作流程中实施，并且可以在CT扫描上精确定位和指定凹口。对于无牙患者，可以使用螺钉进行基于刚性点的配准。但是，建议使用新的螺丝设计，以提高CT扫描上的指定精度。