# Using Markups planes as a bone cut planning for navigation machine

**URL:** <https://discourse.slicer.org/t/using-markups-planes-as-a-bone-cut-planning-for-navigation-machine/44395>\
**Category:** Support\
**Created:** [September 9, 2025, 2:17am UTC](https://discourse.slicer.org/t/using-markups-planes-as-a-bone-cut-planning-for-navigation-machine/44395 "2025-09-09T02:17:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Ben\_Fong](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ben_fong/32/67953_2.png) [@Ben\_Fong](https://discourse.slicer.org/u/Ben_Fong)\
**Post date:** [September 9, 2025, 2:17am UTC](https://discourse.slicer.org/t/using-markups-planes-as-a-bone-cut-planning-for-navigation-machine/44395/1 "2025-09-09T02:17:32Z")

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Hello,

I am working on bone tumour surgery planning. I created planes in Markups for the bone cuts, and would like to convert them to models and then save them as STLs to import to the navigation machine. I have two questions:

1. I used the markuptomodel extension, selected the plane, the name of the plane appears in the model, but there is nothing inside. What have I missed?

2. I would like to have the plane with thickness because real bone cut have thickness. Is there a way to covert the plane into one with thickness (effectively a rectangle)? Or should I use ROI? But then, how can I convert it to a model/stl?

Thanks

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**Author:** ![mau\_igna\_06](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mau_igna_06/32/9056_2.png) [@mau\_igna\_06](https://discourse.slicer.org/u/mau_igna_06)\
**Post date:** [September 9, 2025, 2:29am UTC](https://discourse.slicer.org/t/using-markups-planes-as-a-bone-cut-planning-for-navigation-machine/44395/2 "2025-09-09T02:29:13Z")

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When [this PR](https://github.com/Slicer/SlicerSurfaceToolbox/pull/80) is merged you’ll be able to give thickness to markup planes by creating a narrow box 3D model