How to be able to edit a 3D Model (.stl) keeping high resolution of the output

Hi everyone in this great forum,
I need to modify an .stl file in form of 3D model to be used in another software for orthognathic virtual planning. When I loaded the 3D model to generate a master volume to be then opened in segment editor and when using the erase option the model lost its resolution as You can see this on the image below:

So, is there any option to be able to modify the 3D Model (cutting unneeded parts) having the output 3D .STL Model with high resolution? Would highly appreciate any support.
Thank you so much in advance.
I tried also to use the Dynamic Modeler but I do not know how to apply the cutting tools in this module.

You can edit STL files without losing any relevant details (memory usage and computation time depends on the size of the smallest details need to be preserved). See step-by-step instructions for importing and editing.