FEA of Trinity Miniplate in Maxillofacial Trauma

I want finite element analysis (FEA) of the Trinity miniplate, a medical device used in maxillofacial trauma fixation. Here is a prioritized list of the most important parameters to check in the FEA analysis of the VBH Trinity Mini. Plate:


## Most Important FEA Parameters—VBH Trinity Mini Plate



## Tier 1—Critical (Must Check)

These are the non-negotiable parameters in every mandibular miniplate FEA. In all FEA models, maximum stress consistently remains on the miniplate itself.
1. **Von Mises Stress on the Plate**—Peak stress value (MPa) on the plate body, arm junctions, and screw hole perimeters; must stay below titanium yield strength (~880 MPa)
2. **Von Mises Stress on Cortical Bone**—Peak bone stress at the plate edges and screw purchase zones must stay below ~170 MPa (cortical ultimate strength).
3. **Fracture Gap Micromotion/Displacement—Inter-fragment relative displacement (mm) at the parasymphysis fracture gap; threshold < 150 μm for bone healing
4. **Maximum Principal Stress (Tensile)**—At the lingual cortex where symphyseal fractures initiate under tensile strain.
5. **Minimum Principal Stress (Compressive)**—At the buccal cortex under incisal and molar loading
***

## Tier 2—High Importance

6. **Stress at Screw–Bone Interface**—Contact stress at all 6 screw holes (Ø 1.50 mm); highest risk at holes closest to the fracture gap
7. **Stress Concentration at Plate Edges**—Specifically at the posterior border of the two vertical connecting arms; Graillon et al. found a 50% Von Mises stress increase at plate edges, risking secondary fracture
8. **Stress Shielding Index**—% reduction in bone stress directly beneath the plate; predicts long-term bone resorption risk
9. **Safety Factor (SF)** — \(SF = \frac{\sigma_{yield}}{\sigma_{VM}}\); target SF > 1.5 for the plate under all load cases
10. **Sub-apical to Lower Arm Parallelism**—Maintenance of the constant 4.5 mm inter-arm distance under masticatory and trauma loads; unique to Trinity plate geometry


## Tier 3—Important for Validation & Publication

11. **Mental Foramen Stress Neutrality**—Confirm zero stress concentration at the mental foramen region; validates the Trinity plate's core design advantage over 3D plates
12. **Tensile Failure Load Prediction**—FEA-predicted failure load vs. experimentally measured 649 N (Trinity) and 565 N (conventional SS plate) from your ASTM D 4501 in-vitro study [ppl-ai-file-
13. **Mesh Convergence**—Compare peak Von Mises stress at 1 mm vs. 0.5 mm element sizes until stress becomes mesh-independent. c.ncbi.nlm.nih](https://pmc.ncbi.nlm.nih.gov/articles/PMC12033247/)
14. **Strain Energy Density (SED) in Bone**—Mechanobiological indicator of bone remodeling stimulus around screw holes [sciencedirect](https://www.sciencedirect.com/science/article/pii/S0929664625003985)
15. **Fatigue Life (N cycles)**—Under cyclic masticatory loads (~800 cycles/day) to evaluate long-term plate durability



Quick Reference Summary Table

| Priority | Parameter | Location | Threshold |
|---|---|---|---|
| 1 | Von Mises Stress | Plate | < 880 MPa |
| 2 | Von Mises Stress | Cortical bone | < 170 MPa |
| 3 | Fracture gap micromotion | Inter-fragment | < 150 μm |
4 | Max. Principal Stress | Lingual cortex | Monitor |
| 5 | Min. Principal Stress | Buccal cortex | Monitor |
| 6 | Screw–bone interface stress | All 6 screw holes | Minimize |
| 7 | Stress at plate edges | Vertical arm borders | < 170 MPa bone |
| 8 | Stress shielding | Under plate | Minimize |
| 9 | Safety Factor | Plate | > 1.5 |
| 10 | Inter-arm parallelism | Sub-apical & lower arm | 4.5 mm constant |
| 11 | Mental foramen stress | Foramen region | ≈ 0 MPa |
| 12 | Failure load | Plate–PMMA construct | ≥ 649 N |
| 13 | Mesh convergence | Entire model | Stress-independent |
| 14 | Strain energy density | Periimplant bone | Optimal range |
| 15 | Fatigue life | Plate | > 10⁶ cycles |

The three most fundamental input parameters for any mandibular FEA are bite force, muscle force, and material properties—all other outputs derive from how accurately these are defined.