Converting an open subd to a closed subd

Hi all I made a negative mold of a scan in rhino using the Drape function. Then from that "surface. I added another extruded surface and used BooleanUnion to combine it into a single polysurface. At this point its still a closed Polysurface. Then i used QuadRemesh to convert the Polysurface to a SubD object. Here is where I’m running into the issue; the resulting object is an open SubD not a closed SubD. How do i close this SubD so i can augment it as needed?

Any help on this topic would be GREATLY appreciated

Hi Supraja - ShowEdges > Naked edges will show you where the openings are - that is the first step.

I am not sure Drape was the way to go here - can you QuadRemesh directly ? What is the scan data, points or meshes?