Accuracy of augmented reality navigated surgery for placement of zygomatic implants: a human cadaver study.

Purpose: Placement of zygomatic implants in the most optimal prosthetic position is considered challenging due to limited bone mass of the zygoma, limited visibility, length of the drilling path and proximity to critical anatomical structures. Augmented reality (AR) navigation can eliminate some of the disadvantages of surgical guides and conventional surgical navigation, while potentially improving accuracy. In this human cadaver study, we evaluated a developed AR navigation approach for placement of zygomatic implants after total maxillectomy.

Methods: The developed AR navigation interface connects a commercial navigation system with the Microsoft HoloLens. AR navigated surgery was performed to place 20 zygomatic implants using five human cadaver skulls after total maxillectomy. To determine accuracy, postoperative scans were virtually matched with preoperative three-dimensional virtual surgical planning, and distances in mm from entry-exit points and angular deviations were calculated as outcome measures. Results were compared with a previously conducted study in which zygomatic implants were positioned with 3D printed surgical guides.

Results: The mean entry point deviation was 2.43 ± 1.33 mm and a 3D angle deviation of 5.80 ± 4.12° (range 1.39-19.16°). The mean exit point deviation was 3.28 mm (±2.17). The abutment height deviation was on average 2.20 ± 1.35 mm. The accuracy of the abutment in the occlusal plane was 4.13 ± 2.53 mm. Surgical guides perform significantly better for the entry-point (P = 0.012) and 3D angle (P = 0.05); however, there is no significant difference in accuracy for the exit-point (P = 0.143) when using 3D printed drill guides or AR navigated surgery.

Conclusion: Despite the higher precision of surgical guides, AR navigation demonstrated acceptable accuracy, with potential for improvement and specialized applications. The study highlights the feasibility of AR navigation for zygomatic implant placement, offering an alternative to conventional methods.