Teeth and tongue meshes

Hi all
If I export my mh as an fbx it includes the mouth box but no teeth or tongue. I also cannot find these meshes in the content browser, only the material and textures for them.
Anyone know why this is ?
reason is to model teeth grills around the teeth in blender and then attach the grills as a separate mesh once back in ue so guessing the size isn’t really possible as it would be a wild guess tbh and look pretty bad.
A basic solution could be to paint the teeth texture map but I don’t think this would look great.
Thx!