Bone Resorption Assessment Following Zygomatic Implants Surgery over 10 Years of Follow-Up

The presence of sufficient bone volumes is one of the most important criteria for the success of oral implant osseointegration. Therefore, the rehabilitation of edentulous atrophic maxillae represents the greatest challenge in terms of oral rehabilitation. Techniques such as bone grafts, angled implants, short implants, tuberosity, and pterygoid implants may not always be a viable alternative in the subsequent rehabilitation of the posterior atrophic maxilla. A breakthrough occurred when Brånemark first introduced longer, custom-designed implants inserted into the zygomatic bone to support craniofacial prosthesis in the 1980s. When used in the treatment of atrophic jaws, zygomatic implants provide a safe and effective alternative, with stable long-term results. Objectives: We aimed to retrospectively evaluate zygomatic bone resorption ten years after the placement of zygomatic implants. Methods: A retrospective observational study was designed to evaluate bone resorption over ten years following the placement of zygomatic implants. In a study group of 50 patients, using Hounsfield scales, the area of the zygoma and its bone density were established and evaluated. The NewTom NNT Analysis software (NewTom^®, Imola, Italy) was employed to trace the bone and implant limits on CBCT scans. Using this software, the three-dimensional information of the postoperative CBCT image was compared with the ten-year postoperative CBCT image, allowing for the assessment of the zygomatic bone resorption and bone density. Results: Highly significant statistical differences to an alpha level of 0.01 were identified between T0 (pre-op), T1 (12 months), and T2 (120 months) concerning zygomatic bone density, both in the first and in the second quadrants. The post hoc Bonferroni test revealed that significant statistical differences were observed between T0 and the remaining timepoints (T1 and T2), with the latter two exhibiting similar values. Conclusions: The evaluation of the resorption at the level of the zygoma, ten years after the placement of zygomatic implants, reveals that there are no significant losses between the initial and final controls. Therefore, it follows that this type of implant rehabilitation represents a viable alternative approach in patients with bone atrophy of the maxilla, offering a predictable therapeutic solution that enables immediate full function and excellent long-term success rates. However, we must not neglect the potential for future innovations in GBR involving the use of barrier membranes, either resorbable or non-resorbable, and even the application of titanium alveolar customized osteogenic scaffold, in conjunction with autologous bone grafts or biomaterials.