Biomechanical evaluation of fixation systems in different segmental Le Fort I osteotomies: Patient-specific implants versus miniplates.

BACKGROUND

Patient-specific implants (PSIs) are increasingly used in orthognathic surgery; however, their biomechanical performance in multi-segment Le Fort I osteotomies has not been fully clarified.

OBJECTIVE

To compare stress distribution and mechanical stability of PSIs and conventional miniplates in two- and three-piece segmental Le Fort I osteotomies using finite element analysis.

MATERIALS AND

METHODS

Four three-dimensional maxillary models were constructed with 5 mm advancement and 5 mm expansion. Each model was fixed with either PSIs or miniplates. Oblique (30°) and vertical (125 N) forces were applied to the premolar-molar region. Maximum and minimum principal stresses in bone and von Mises stresses in fixation plates were analyzed.

RESULTS

Three-piece osteotomies with miniplates exhibited the highest stress concentrations in both bone and plates. PSI fixation consistently reduced stress magnitudes and promoted more uniform load transfer under both oblique and vertical loading.

SIGNIFICANCE: Compared with conventional miniplates, PSIs may provide enhanced biomechanical stability in segmental Le Fort I osteotomies; however, further clinical validation is required.