TopoRelax is a 3ds Max modifier which relaxes meshes while preserving their volume unlike the normal relax modifier which shrinks the mesh.
Here are some of the benefits you get:
You don’t have to worry about meshes losing their volume while you relax them.
You get a nice evenly distributed quad mesh.
You can be happy about a nice smooth mesh.
Situations in which you would want to use TopoRelax modifier:
When you want to have an evenly distributed quad mesh for sculpting.
When you want to produce morph targets.
When you want to smooth out a mesh to remove unwanted artifacts.