Accuracy of drilling guides for transfer from three‐dimensional CT‐based planning to placement of zygoma implants in human cadavers

TLDR

The study assessed the accuracy of surgical drilling guides for placing zygoma implants. Six 45‑mm zygoma fixtures were placed in three cadavers using custom 3D‑CT‑based drilling guides, with pre‑ and postoperative imaging used to measure implant deviation. Implant placement deviated less than 3° in four of six cases, with a maximum exit‑point deviation of 2.7 mm, supporting the use of drilling guides for zygoma implants.

Abstract

Abstract: The accuracy of surgical drilling guides was assessed for placement of zygoma implants. Six zygoma fixtures of length 45 mm (Nobel Biocare, Göteborg, Sweden) were placed in three formalin‐fixed human cadavers using surgical drilling guides. The fabrication of these custom‐made drilling guides was based on three‐dimensional computerized tomography (3D‐CT) data for the maxillary‐zygomatic complex. The installation of the implants was simulated preoperatively using an adopted 3D‐CT planning system. In addition, anatomical measurements of the zygomatic bone were performed on the 3D images. The preoperative CT images were then matched with postoperative ones in order to assess the deviation between the planned and installed implants. The angle between the planned and actually placed implants was < 3° in four out of six cases. The largest deviation found at the exit point of one of the six implants was 2.7 mm. The present study showed that the use of surgical drilling guides should be encouraged for zygoma implant placement because of the lengths of the implants involved and the anatomical intricacies of the region.