Combined static and dynamic computer-guided surgery for prosthetically driven zygomatic implant placement.

Objectives: To propose and validate a minimally invasive combined static and dynamic computer assisted implant surgery (CAIS) workflow for zygomatic implant (ZI) placement.

Methods: A combined approach leveraging static CAIS for initial positioning, complemented by dynamic CAIS for real-time control of the angle, depth and width was proposed. Fourteen consecutive patients (age: 60.3±9.8 years; 8 females) seeking ZI-supported restoration were enrolled. A single anatomically and prosthetically driven ZI on either the unilateral zygoma or bilateral zygomata was planned and placed using the proposed approach. The zygomatic anatomy-guided approach (ZAGA) type and the ZI length were recorded. The angular, coronal global, and apical global deviation between the planned and placed positions were measured by overlapping post- and pre-operative cone beam computer tomography. Comparisons were made between the left and right sides across the ZAGA type and ZI length. Statistical significance was set at P<0.05.

Results: 22 ZIs were placed using the combined approach and 13 immediate loading prostheses were delivered, with one patient restored 6 months after surgery. The angular deviations and coronal global deviations were 1.99±0.17° and 1.21±0.45 mm, respectively. The median apical global deviation was 1.67 mm (interquartile range [IQR]: 1.11-1.93 mm). No significant differences were found between the left and right sides across the ZAGA type or ZI length. All ZIs remained stable over a median follow-up of 14.5 months (IQR: 7-20 months).

Conclusions: The proposed combination of static and dynamic CAIS is safe, reliable, accurate, and robust for ZI placement.

Clinical Significance: This pilot study proposed a minimally invasive ZI placement method that combined static and dynamic computer-guided surgery. The implant positioning accuracy achieved using this approach validated its safety, reliability, accuracy, and robustness. The combined approach may reduce the technique sensitivity of ZI placement, facilitating future rehabilitation of severely atrophic or defective maxillae.