Agreed on the fingerprints. On DNA, it is expensive and takes a long time compared to dental records which are readily available. So I don’t think you’d even think about DNA if you have dental impressions to compare.
They may have also done DNA, to be doubly-sure.
We were just told they used dental records.
In this day and age there does need to be a very specific, independent identification of the decedent, especially with a murder and a concealed body.
I would not go too far in presuming that dental records means something really awful, other than she was deceased and, sadly, some means of her death may have made facial recognition less likely. I'm thinking a gunshot injury. My supposition is also that she did not have on the clothing she was last seen in, and perhaps all the other LE investigation of the grounds around the home and/or the garage are looking for these items.