Assessing the Clinical Relevance of Finite Element Models in MARPE-Induced Behaviour of Craniofacial Structures: A Critical Review

Background/Objectives: Miniscrew-Assisted Rapid Palatal Expansion (MARPE) has emerged as a widely adopted, non-surgical intervention for maxillary transverse deficiency (MTD) in adolescents and adults. Despite favourable clinical outcomes, treatment responses remain unpredictable due to anatomical variability and biomechanical complexities. This narrative review aims to evaluate the methodological robustness and translational potential of finite element method (FEM) models in simulating MARPE-induced craniofacial biomechanics. Methods: A structured literature search across five electronic databases, supplemented with AI-assisted screening tools, identified 70 relevant publications. Among these, 14 studies met the inclusion criteria for FEM-specific analysis, and 6 incorporated elements of clinical validation. The review critically assessed modelling practices, material assumptions, mesh characteristics, boundary conditions, and validation strategies. Results: FEM has proven effective in visualising stress distribution, displacement patterns, and mechanical thresholds in craniofacial structures during MARPE. However, significant methodological limitations were observed, including oversimplified geometries, lack of patient-specific imaging, reliance on isotropic and linear-elastic material assumptions, and insufficient clinical validation. These deficiencies reduce the predictive accuracy and clinical relevance of current FEM studies. Conclusions: To enhance the clinical applicability of FEM in MARPE research, future models should integrate anatomically accurate reconstructions, biologically informed boundary conditions, and longitudinal validation using CBCT data. Such advancements will enable evidence-based, patient-specific treatment planning and contribute to safer and more predictable orthodontic outcomes.