Minimally Invasive Navigation-Guided Quad Zygomatic Implant Placement: A Comparative In Vitro Study.

Zygomatic implants (ZIs) have been considered a reliable alternative treatment for patients with maxillary atrophy and/or maxillary defects. The use of a navigation system for assisting ZI placement could be a reliable approach for enhancing accuracy and safety. The purpose of this in vitro study was to evaluate the accuracy of a new dynamic surgical navigation system with its minimally invasive registration guide for quad zygomatic implant placement in comparison with a gold standard navigation approach. A total of 40 zygomatic implants were placed in 10 3D-printed models based on the CBCT scans of edentulous patients. For registration, a surgical registration guide with a quick response plate was used for the test group, and five hemispheric cavities as registered miniscrews in the intraoral area were used for the control group. In each model, a split-mouth approach was employed (two ZIs in bilateral zygomata) to test both systems. After ZI placement, a CBCT scan was performed and merged with pre-interventional planning. The deviations between planned and placed implants were calculated as offset basis, offset apical, and angular deviation and compared between the systems. The offset basis, offset apical, and angular deviation were 1.43 ± 0.55 mm, 1.81 ± 0.68 mm, and 2.32 ± 1.59 degrees in the test group, respectively. For the control group, values of 1.48 ± 0.57 mm, 1.76 ± 0.62 mm, and 2.57 ± 1.51 degrees were measured without significant differences between groups (all < .05). The accuracy of ZI positions (anterior and posterior) were measured without significant differences between groups. Two navigation systems with different registration techniques seem to achieve comparable acceptable accuracy for dynamic navigation of zygomatic implant placement. With the test group system, additional pre-interventional radiologic imaging and invasive fiducial marker insertion could be avoided.