Biomechanical Interaction Between Endosseous and Patient-Specific Subperiosteal Implants in Full-Arch Rehabilitation of the Atrophic Maxilla: A Finite Element Analysis.

PURPOSE: To compare the biomechanical behavior of a hybrid maxillary full-arch reconstruction supported by conventional endosseous implants and a patient-specific subperiosteal implant with a reconstruction supported by bilateral patient-specific subperiosteal implants.

MATERIALS AND

METHODS

Three-dimensional finite element models of a severely atrophic maxilla were constructed from computed tomography data. Two full-arch prosthetic configurations were analyzed: a hybrid model (three endosseous implants on one side and a patient-specific subperiosteal implant on the contralateral side) and a bilateral model (bilateral subperiosteal implants). Three static loading conditions were simulated: bilateral posterior vertical (900 N), unilateral posterior oblique (300 N), and bilateral anterior vertical (600 N). Maximum principal stress in bone, von Mises stress in metallic components (implant frameworks, conventional implants, and fixation screws), and total prosthetic displacement were assessed using nonlinear static analysis.

RESULTS

Global peak values of stress and displacement were slightly higher in the bilateral subperiosteal model across all loading scenarios. Maximum principal stress in maxillary bone ranged from 6.777 to 16.687 MPa in the hybrid configuration and from 7.255 to 17.674 MPa in the bilateral configuration. Peak von Mises stress in the implant systems reached 140.076 MPa in the hybrid model (concentrated in the subperiosteal framework) and 146.170 MPa in the bilateral model, whereas the maximum stress in endosseous implants was 57.88 MPa. Prosthetic displacement ranged from 0.01598 to 0.10110 mm in the hybrid model and from 0.01611 to 0.10360 mm in the bilateral model. Despite comparable global peaks, the hybrid configuration exhibited an asymmetric spatial distribution, with stress and displacement concentrating predominantly on the subperiosteal implant-supported side.

CONCLUSIONS

Splinting conventional endosseous and patient-specific subperiosteal implants within a single maxillary full-arch prosthesis did not increase global peak stresses or prosthetic displacement compared to bilateral subperiosteal reconstruction under the simulated conditions. However, the hybrid configuration induced a more asymmetric cross-arch biomechanical response under the simulated conditions.