A patient-specific PEEK fixation system for simultaneous maxillary advancement and midfacial contour restoration in Le Fort I osteotomy: A finite element analysis

Abstract

Background

Severe maxillary hypoplasia often requires combined skeletal repositioning and midfacial contour restoration. While Le Fort I osteotomy effectively addresses dental and skeletal discrepancies, residual midfacial deficiencies — such as infraorbital depression and paranasal flatness — frequently persist, necessitating additional soft tissue or alloplastic procedures. This study introduces a novel patient-specific polyetheretherketone (PEEK) fixation system designed to simultaneously stabilize Le Fort I-advanced maxillary segments and restore midfacial morphology in a single surgical stage.

Methods

A customized PEEK plate was digitally designed to match both the ideal bony anatomy and the desired facial profile. Finite element (FE) models were developed to compare the biomechanical performance of the PEEK fixation system with that of a conventional titanium fixation system under simulated physiological bite forces. Outcomes assessed included intersegmental maxillary displacement, von Mises stress distribution in the bone and implants, and screw stress levels.

Results

The PEEK fixation system demonstrated comparable maxillary stability to titanium fixation, with reduced overall displacement (0.08416 mm vs. 0.09285 mm) and a more physiologically balanced stress distribution across the maxillary buttresses. Screw stresses were slightly higher in the PEEK system (515.8 MPa vs. 414.2 MPa), but remained well below material yield limits (titanium alloy (TC4) ≈ 860 MPa). The externally contoured PEEK plates also facilitated direct midfacial contouring, eliminating the need for secondary soft tissue augmentation. Three-dimensional axis-wise analysis showed PEEK had lower Z-axis displacement (0.03178 mm vs. 0.07787 mm) and more uniform displacement fields, further supporting its enhanced segmental stability.

Conclusions

This study suggests that a patient-specific PEEK fixation system can safely and effectively stabilize Le Fort I-advanced maxillary segments while concurrently addressing midfacial contour deficiencies. This integrated approach demonstrates potential advantages in postoperative stability, functional recovery, and aesthetic outcomes, supporting its future clinical application as a streamlined solution for combined skeletal and soft tissue reconstruction.