COMPARISON OF ONE– AND TWO–PIECE PATIENT SPECIFIC IMPLANTS FOR VARIOUS MOVEMENTS OF MAXILLA IN LEFORT I SURGERY: A FINITE ELEMENT ANALYSIS

Year 2025, Volume: 49 Issue: 2, 64 - 70, 28.08.2025

Onur Koç , Hakan Tüz

Abstract

Background and Aims: The present finite element analysis
(FEA) was performed to determine whether one–piece patient
specific implants (PSI) are superior to two–piece implants
in terms of the distribution of occlusal forces and limiting
translocation during the healing period of LeFort I surgery.
Materials and Methods: The models were generated for
5 mm advancement, 5 mm setback, 5 mm impaction, and 5
mm downward positioning of the maxilla, following contact
analysis of the screws, cortical bone, and cancellous bone. One–
and two–piece PSIs were inserted into the aforementioned four
models, and a vertical force of 98 N was applied bilaterally to the
premolar and molar teeth. The von Mises stress was evaluated
for the PSIs, screws, and adjacent bones. Translocation amounts
and patterns were evaluated for the maxillary components of
the models.
Results: The maximum von Mises stresses of one–piece
PSIs for the advancement, setback, downward positioning,
and impaction models were 233 MPa, 248 MPa, 263 MPa,
and 260 MPa, respectively. The maximum von Mises stresses
of two–piece PSIs for the advancement, setback, downward
positioning, and impaction models were 248 MPa, 256 MPa,
250 MPa, and 270 MPa, respectively.
Conclusions: The stress distribution on the PSIs did not differ
between the one-piece and two–piece PSIs for all movement
models. Two–piece PSIs can be preferred over one–piece PSIs
for increased adaptability without loss in strength.

Keywords

Finite Element Analysis , Lefort I , Patient Specific Implant , Stress Distribution , Von Mises Stress

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