Problem with imported model's face partitioning in COMSOL

[BEStudent]

Hi,

for my engineering thesis I need to analyze denture model (from 3D scan) in COMSOL. The problem is that when I import my model to COMSOL it has some random face distribution and I can't apply boundary conditions precisely.
I've found one way to get better face partitioning - predefine it in Gmsh software, export as BDF (Nastran format) and import to COMSOL as mesh (not geometry like I was trying before). But even if I do that COMSOL still merges triangles and creates too big, quadrangular regions for applying boundary conditions. It can be seen on attached pictures. Only bold lines from "Mesh node view" picture are preserved as partitioning and thin ones disappear as shown on Physics node view" picture.

I will be grateful for any help. Also if you know someone who can help or some forum where I should ask (I didn't get a reply on COMSOL Discussion forum) please let me know.