Two STL models of Intra- oral surface scan alignment and volume measurement

Hi,

Our Input - 2 STL surface scan models (PreOp and Post Op) - from the 3Shape surface scanner.

We have two problems.

  1. Need to accurately align the pre and post op surface scans ? (they have fixed landmarks)

  2. Need to measure the change of volume in the region of interest ? ( the volume of bone resorption)

So far, we have install CMF registration and,

as you can see from the pictures the alignment with CMF surface registration is not accurate enough.

PreOperative

We need to improve the accuracy of the alignment and we are unable to do it so far.

Can someone help us with accurate alignment/superimposition of the two scans ?

Next we need to measure the change in the bone volumes in the circled region. That is the difference of bone volume in preoperative and postoperative scans.

Is this can be done in 3d Slicer ?

Looking forward to hearing from you all.

Thanks