Three-dimensional imaging in virtual surgery planning — patient-specific solution

Abstract Background Virtual surgery planning (VSP) is believed to reduce inaccuracies in maxillary positioning compared to conventional surgery planning (CSP) due to the elimination of face-bow transfer and laboratory steps. However, there is still a lack of comparative studies for the accuracy of splint-based maxillary positioning in CSP versus VSP. Therefore, the objective of this retrospective, observational study was to compare if splints produced by VSP and CSP reach postoperative outcomes within clinically acceptable limits. Methods The planned and actual postoperative results of 52 patients (VSP: n = 26; CSP: n = 26) with a mean age of 24.4 ± 6.2 years were investigated by three-dimensional (3D) alignment with planning software. The conventional treatment plan was digitized, so that the evaluation of both methods was performed in the same manner using the same coordinate system. Inaccuracies were measured by sagittal, vertical and transversal deviations of the upper central incisors and the inclination of the maxillary occlusal plane between the planned and achieved maxillary positions. Results Both methods demonstrated significant differences between the planned and actual outcome. The highest inaccuracies were observed in vertical impaction and midline correction. No significant differences between CSP and VSP were observed in any dimension. Errors in vertical and sagittal dimension intensified each other. Conclusions In conclusion, splint-based surgeries reached similar results regardless of the applied planning method and splint production.

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Evaluation of in-house, haptic assisted surgical planning for virtual reduction of complex mandibular fractures

International Journal of Computer Assisted Radiology and Surgery ◽

10.1007/s11548-021-02353-w ◽

2021 ◽

Author(s):

Johanna Nilsson ◽

Fredrik Nysjö ◽

Ingela Nyström ◽

Johan Kämpe ◽

Andreas Thor

Keyword(s):

Computed Tomography ◽

Surgical Planning ◽

Maxillofacial Surgery ◽

Three Dimensional ◽

Planning System ◽

Virtual Surgery ◽

Mandibular Fractures ◽

Surgery Planning ◽

Anatomic Reduction ◽

Mandible Fractures

Abstract Purpose The management of complex mandible fractures, i.e. severely comminuted or fractures of edentulous/atrophic mandibles, can be challenging. This is due to the three-dimensional loss of bone, which limits the possibility for accurate anatomic reduction. Virtual surgery planning (VSP) can provide improved accuracy and shorter operating times, but is often not employed for trauma cases because of time constraints and complex user interfaces limited to two-dimensional interaction with three-dimensional data. Methods In this study, we evaluate the accuracy, precision, and time efficiency of the haptic assisted surgery planning system (HASP), an in-house VSP system that supports stereo graphics, six degrees-of-freedom input, and haptics to improve the surgical planning. Three operators performed planning in HASP on computed tomography (CT) and cone beam computed tomography (CBCT) images of a plastic skull model and on twelve retrospective cases with complex mandible fractures. Results The results show an accuracy and reproducibility of less than 2 mm when using HASP for virtual fracture reduction, with an average planning time of 15 min including time for segmentation in the software BoneSplit. Conclusion This study presents an in-house haptic assisted planning tool for cranio-maxillofacial surgery with high usability that can be used for preoperative planning and evaluation of complex mandible fractures.

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