Measuring displacement of the zygoma bone after surgery

[muratmaga]

@MAXFAXSURGEON

So, when I finished doing RIGID REGISTRATION I need to save Volume as seen in the attached screenshot ( in which format should be saved?)

Use NRRD, which is the default format in Slicer.

@MAXFAXSURGEON

After saving the required output, the next step to do segmentation for both Oriented T1 and saved output volume: should be done for each one separately or can be done for both of them?

You need to clean the thin shell around the skull. If you are not familiar with segmentation in Slicer, you probably need to read this documentation first:
https://slicer.readthedocs.io/en/latest/user_guide/image_segmentation.html
and this
https://slicer.readthedocs.io/en/latest/user_guide/modules/segmenteditor.html

You need to do this both for your new volume and T1

@MAXFAXSURGEON

in which format should I save the segmentation to be modelled in the next step? I can not see here .stl format.

seg.nrrd is the default format for segmentation

@MAXFAXSURGEON

After saving the proper format afte segmentation, what is the next step tp create a model for Oriented T1 and output volume?

You can go to the Segmentations module and export your segmentation as a 3D model with a single click (Import/Export tab).