CBCT volumetric alveolar comparison before after bone graft

[Zah]

Hi there, I am totally new to slicer and would like to use it for a research study where volumetric changes of alveolar bone is measured before and after grafting. I have gone through the tutorials and there is a quantitative imaging tutorial, however this is only helpful in measuring volumetric change in pathologic lesions with well circumscribed margins. I basically need to align and superimpose two dicom images T1 and T2 and measure horizontal and vertical difference between the two over a defined area, an extraction socket. I would greatly appreciate it if someone could point me in the right direction.