# Problem with mandibular plane in bone reconstruction planner
**URL:** https://discourse.slicer.org/t/problem-with-mandibular-plane-in-bone-reconstruction-planner/43511
**Category:** Support
**Tags:** surgical-planning
**Created:** [June 27, 2025, 3:08am UTC](https://discourse.slicer.org/t/problem-with-mandibular-plane-in-bone-reconstruction-planner/43511 "2025-06-27T03:08:23Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Marco\_Sarcinella](https://discourse.slicer.org/u/Marco_Sarcinella)
#### Post date: [June 27, 2025, 3:08am UTC](https://discourse.slicer.org/t/problem-with-mandibular-plane-in-bone-reconstruction-planner/43511/1 "2025-06-27T03:08:23Z")
Hi! I’m new in 3slicer, i had only one case of mandibulectomy in 3 d slicer the past month.
Now I’have a problem when i do te positioning of mandibolar plane. Why when i set mandibular plane in correct position they cut off a piece of contralateral mandible ? So i can’t have a pre plating model to print with all the mandible .
For Example i had to do a recostruction of left ramus. When i set my 3 mandibular plane, the “prolong” the cut also in the right ramus, cutting condile and other pieces.
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### Author:  [@mau\_igna\_06](https://discourse.slicer.org/u/mau_igna_06)
#### Post date: [June 27, 2025, 1:22pm UTC](https://discourse.slicer.org/t/problem-with-mandibular-plane-in-bone-reconstruction-planner/43511/2 "2025-06-27T13:22:17Z")
Hi
Please check this:
>
>
> Hello ! And thank you for sharing your experience . I have a problem when i out …mandibular plane in bone recostruction panel.
> When I put them, the cut also a part of controlateral mandible non included in the resection, with the consequence that is impossible to print a model with a contralateral side like the original
It should solve the problem
Mauro
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### Author:  [@Marco\_Sarcinella](https://discourse.slicer.org/u/Marco_Sarcinella)
#### Post date: [October 17, 2025, 9:05am UTC](https://discourse.slicer.org/t/problem-with-mandibular-plane-in-bone-reconstruction-planner/43511/3 "2025-10-17T09:05:48Z")
Hi mauro ! How are you ?
First thanks for your suggests and your work! Thank you so much.
I would like to ask you another advice.
When designing a surgical guide for the fibula, there is often a tendency to design the guide to fit perfectly to the bone.
This is a big problem because, although you always try to preserve the periosteum on the lateral side of the fibula, there are muscle insertions on the anterior/medial side that make the fibula thicker than the bone portion alone.
How can I generate a surgical guide that is 1-2 millimeters wider?
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### Author:  [@Marco\_Sarcinella](https://discourse.slicer.org/u/Marco_Sarcinella)
#### Post date: [October 17, 2025, 9:08am UTC](https://discourse.slicer.org/t/problem-with-mandibular-plane-in-bone-reconstruction-planner/43511/4 "2025-10-17T09:08:37Z")
Is possible for example to :
A-Hollow the fibula 1-2 millimetres
B-add another segment and hollowing it for the surgical guide , based on precedent hollwing (letter A). And Using this for the fibula surgical guide ?
Thank you !!!
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### Author:  [@mau\_igna\_06](https://discourse.slicer.org/u/mau_igna_06)
#### Post date: [October 20, 2025, 6:42pm UTC](https://discourse.slicer.org/t/problem-with-mandibular-plane-in-bone-reconstruction-planner/43511/5 "2025-10-20T18:42:06Z")
After you create the `hollow` guidebase, you should be able to use `margin` effect with a negative value to get the result you are looking for