their incinerated remains after the crash will be that much more difficult to identify.
We were told, with memorable illustrations, on a course on dealing with air accidents some years ago, that it's quite normal to recover the teeth from the seat cushion in which they became lodged after passing through the body, itself rather compressed, after a high-speed downwards impact. (With a forward impact the teeth tend to end up in the seat in front.) The teeth do not usually separate from the skull or jawbone, thus preserving an identifiable and unique feature of a victim.
So knowing who was in what seat is always a help, but not the only way of doing it, and can be unreliable. Teeth are much better in these days of dentistry that's universally well documented except in Russia, parts of China and the Far East, and Africa. And of course Leeds.
I thought you would want to know this.