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virtual metal plate registration for orbital fracture

Key Investigators

• Chi Zhang, PhD (Texas A&M University School of Dentistry, USA)
• Andrew Read-Fuller, MD, DDS (Texas A&M University School of Dentistry, USA)
• Braedon Gunn (Texas A&M University School of Dentistry, USA)

Presenter location: Online

Project Description

Orbital fracture usually involve large areas in the floor and medial wall of the orbit. During surgery, surgeons usually remove cracked floor and medial wall of the orbit and use the plate to reconstruct the orbit. Thus, we aim to develop a module for register 3D model of preformed metal plates to orbital fracture sites for surgical planning and measuring the adaptability of plates to patients. The registered plate should sit just above the unfractured bone of the orbit.

(MatrixORBITAL™ Preformed Orbital Plates)

Objective

1. Simulate the process of how surgeons would place the plate to fracture sites:

   • Plate can only rotate as it is fixed at the landmark “posterior stop, which marks the orbital process of the palatine bone. This area is usually preserved in orbital fracture cases and the most important landmark to screw the plate.
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   • Allow the plate sit above the unfractured area of the orbit rather than being superimposed with the orbit.

2. Interactive tool for fine tuning the plate registration, such as adding an interactive handler for the 3D model.

3. Automated segmentation of the fractured orbit as a future goal.

Approach and Plan

1. Using Fiducial Registration Wizard to do a pre-registration of the plate to the fractured orbit, then further registration the posterior stop landmark on the plate to the actual posterior stop on the orbit.
2. Improved registration based on only allow the plate to rotate around the posterior stop: select more surgical landmarks at the peripheral areas of the orbit and the plate. Register the plate again with it pivoted on the posterior stop.
3. Further refined registration to allow the plate to sit above the unfractured bone of the orbit.
4. Add an interactive handler for adjusting the plate manually.

Progress and Next Steps

1. I am able to make the plate landmark set to rotate around a particular landmark, the posterior stop, to do a rigid registration by changing the rotation center from the centroid to the posterior stop and then do a singular value decomposistion to generate a transformation matrix.

2. The imporved interaction handle widget by Kyle Sunderland (https://projectweek.na-mic.org/PW40_2024_GranCanaria/Projects/NewInteractionWidgetForTransformsMarkups/) has lots of potential for fine tuning the plate position after an initial plate registration. I can drag the center of rotation of the handle to the posterior stop or set up a rotation center in Python to rotate the plate around the posterior stop. I will discuss with the surgeon I am working with about some potential usage and perhaps new development for the plate registration.

1. The challenging is to further rotate the plate until it sits above the unfractures bone of the orbit.

Illustrations

No response

Background and References

No response