Three-dimensional assessment of the malar bone implant engagement of 100 zygomatic implants: a retrospective study

This study was performed to evaluate the amount of bone implant engagement (BIE) of zygomatic implants (ZIs) at the malar bone level and its correlation with the ZAGA classification (zygoma anatomy-guided approach). One hundred ZIs placed in 32 patients with severe maxillary atrophy using a fully digital protocol were assessed: 80 placed in pairs (40 anterior (AI), 40 posterior (PI)) and 20 as single ZIs (SI). The ZAGA classification was determined preoperatively. Postoperative computed tomography scans were analysed using 3D Slicer to measure medial and lateral BIE, the mean value of these (mvBIE), and the ferrule area. Comparisons of the mean mvBIE of the implants (AI, PI, SI) were made according to the ZAGA categories and within each ZAGA group. Descriptive statistics and a linear mixed-effects model were performed (α = 0.05). The overall mean mvBIE was 12.38 ± 3.53 mm (AI: 12.38 ± 3.85 mm, PI: 11.50 ± 3.01 mm, SI: 14.16 ± 3.32 mm). A significant relationship was found between mvBIE and the ZAGA classification (0.005