Quantitative analysis of deviation with superimposed dental arches

Hello everyone
I’m quite new to the slicer software, so please be kind to the rookie :smiley:
I’m doing my master thesis in the field of orthodontic tooth movement. One of my tasks is to quantitatively analyze dental arches. This means I have for example an intraoral scan (STL file) of the patients teeth (one for upper and one for lower arch) before and treatment happened, and a scan after the treatment. What I want to know is how much did every single tooth move. For this, I need to set a global coordinate system which should be the same for the compared (before and after treatment) arches. Looking at literature, there are various ways to do this. I was able to superimpose two STL models with some manually set reference points. This works quite well. I was also able to generate a deviation map. But this only indicates a more qualitative analysis. Is there a package/method where I can do the segmentation for teeth/gingiva where I get local coordinte systems for each tooth, and then calculate the translational matrix for each tooth between initial and post-treatment state? Let’s say by doing a least square fit for the corresponding teeth.