Study introduces new surgical guide for placement of zygomatic implants
BOLOGNA, Italy/FORT LEE, N.J., US: Dental patients who show a deficiency of bone volume cannot be treated with root-form dental implants. Thus, new treatment modalities were sought for these patients. One of the therapies considered was the placement of zygomatic implants, which were introduced to the market over 20 years ago. A recent study has investigated a novel protocol for the placement of zygomatic implants using a specific surgical guide.
The protocol relied on large field of view CT/CBCT scan for an accurate assessment of the maxillary arch to plan zygomatic implant receptor sites. A CT/CBCT-derived surgical guide of a novel design and an exact replica of the entire maxilla and zygomatic bone were fabricated using 3-D printing technology. Four patients with completely edentulous maxillary arches received a total of ten zygomatic implants.
To evaluate whether the actual surgical placement of the zygomatic implants matched the computerised planning and simulation, the preoperative positions were compared with the postoperative positions by merging the pre- and postoperative scan data sets. The degree of accuracy of the superimposition was measured utilising sophisticated software. Apical, coronal and angular deviations were determined for each implant. Deviations from the computerised project to the actual implant positions ranged from 2 mm to 3 mm, and angular deviations ranged between 1.88° and 4.55°.
The study found that the placement of zygomatic implants requires surgical experience owing to the close proximity of vital anatomical structures. It used methods of superimposition that illustrated satisfactory correspondence between inserted implants and the virtual plan. No adjacent vital anatomical structures were damaged. The novel surgical guide design afforded the surgeon visual control of the drilling protocol. Positioning the guide in close proximity to the entry point of the zygomatic body aided control of the drills up to the vicinity of the exit point, significantly limiting problems associated with angular deviation.
The researchers concluded, “Reducing errors and complications is essential for zygomatic implants to remain a viable treatment alternative, and further research on a guided approach to their placement is encouraged.”
The study, titled “Computer-guided approach for placement of zygomatic implants: Novel protocol and surgical guide”, was published in the June 2019 issue of Compendium.