question about labeling cranial foramina of a surface-based (STL) cranial model

[Michel Audette]

Dear members of the ITK Snap community, 

I have a newly purchased commercial digital cranial model, which is simply a collection of STL files of surface components: the cranium itself, jaw bone, teeth, etc. I would like to use ITK Snap to identify the blobs coinciding with cranial openings (foramina). Is something like this feasible just from an STL-based surface model, or must we in fact define a high-res CT-like high-res image in order to voxelize these blobs? 

Thanks for your support. 

Michel Audette