09h40 3D Finite Element Analysis of Biomechanical strains in Patients with Full Titanium Framework on Four Zygomatic Fixtures: systematic review and clinical application

Keywords: Finite Element, Zygomatic Fixtures, Biomechanical, Tridimensional.

Objectives: the position of zygomatic fixtures relative to the maxilla (intra-transsinusal or extra-maxillary) may affect biomechanical strains, potentially causing clinical complications. Finite Element (FE) analysis can predict biomechanical behavior of zygomatic fixtures, surrounding bone, and prosthesis. This study systematically reviews FE analyses of zygomatic fixtures and illustrate a case in order to establish new 3D FE analysis guidelines for predicting biomechanical behavior based on placement techniques.

Material and Methods: a PRISMA-based systematic review was conducted using five data sources (PubMed, Scopus, Elsevier Direct Science, Springer Link, Cochrane Library). Inclusion criteria: (1) FE studies, (2) edentulous/severely atrophic maxilla treated with implant-supported prosthesis, (3) no bone defects from tumors or congenital abnormalities, (4) zygomatic implants, (5) male and/or female participants, (6) publications in English or French. Ten studies were qualitatively analyzed for modeling approaches and FE calculation steps. Additionally, a 3D FE analysis was performed on a patient with a full titanium framework supported by four zygomatic fixtures. Von Mises stress and strain distributions were analyzed for different fixture placement approaches.

Results: of 329 titles identified, 68 full-text articles were reviewed, and 10 met inclusion criteria. The Brånemark technique, introduced in 2007, was the most modeled, appearing in six studies. The extra-maxillary approach, introduced in 2012, was featured in four studies, while the extrasinusal technique appeared in five. Maximum stress values across studies remained within acceptable limits (<900 MPa). In our 3D FE analysis, extrasinusal positioning provided the most favorable stress distribution and deformation for bone, fixtures, and prosthesis.

Conclusion: following the systematic review of the literature, studies on FE analysis of zygomatic implants primarily focus on theoretical models. We propose that 3D Finite Element analysis of real patients be implemented, as it allows for a more accurate comparison of the biomechanical behavior of bone, implants, and prosthesis.