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Updated: Sep 11, 2025
A Postoperative Evaluation Guideline for Computer-Assisted Reconstruction of the Mandible
Published on: January 28, 2020
Accuracy of maxillary repositioning in le fort I osteotomy using a mixed reality based navigation system versus
Cheng Ma1, Shi-Xi He1, Yin-Yu Shang1
1Department of Oral and Maxillofacial Surgery, College & Hospital of Stomatology, Guangxi Medical University, Shuangyong Road 10, Nanning, Qingxiu District, Guangxi, China.
Objective:
Accurate maxillary repositioning is essential for successful outcomes in orthognathic surgery. Current studies on mixed reality (MR) navigation are limited and lack comparison. This study developed an MR-based navigation system and compared it with computer-aided design/computer-aided manufacturing (CAD/CAM) splints and patient-specific surgical plates (PSSPs) in Le Fort I osteotomy.
Methods:
An adjacent-display MR system with optical tracking and automated registration was developed for real-time surgical guidance. Thirty 3D-printed maxillary models were equally assigned to three groups (n=10 each): MR, CAD/CAM splints, and PSSPs. Eighteen human cadaveric specimens were randomly allocated to the MR or PSSP groups (n=9 each). All procedures were performed by the same surgical team.Outcomes included centroid, translational (X, Y, Z), rotational (pitch, yaw, roll), and surface deviations; operative time; and intraoperative adjustments. Deviations were assessed by aligning the planned and postoperative STL files, followed by quantitative and visual analyses using angular plane measurements and color-coded 3D deviation maps.
Results:
In models, MR and PSSPs showed significantly lower centroid, vertical, and pitch errors than did CAD/CAM splints. In cadavers, MR had better pitch accuracy than that of PSSPs. Mean surface deviation was 0.73 and 1.04 mm for MR and PSSPs, respectively. Compared to PSSPs, the MR group had a slightly longer operative time but fewer intraoperative adjustments, with no significant differences.
Conclusion:
MR-based navigation demonstrated superior repositioning accuracy relative to CAD/CAM splints in models and improved pitch control over PSSPs in cadavers.
Clinical Significance:
The proposed MR system may support surgeons during Le Fort I osteotomy by improving the precision and real-time controllability of maxillary repositioning.
