In another book (I can’t remember which, but for some reason I’m thinking of Salem’s Lot), after cutting off the vampire’s head, they turned it backwards in the coffin. Why, I don’t know.
Has anyone else heard of this before?
Yes, somewhere. The book is probably with my copy of Dracula. 
Okay, okay…can anyone explain the significance of turning the head backwards in the coffin?
Well, some cultures believed that a vampire would have to dig his way out of a coffin with his teeth, as there isn’t enough room to use your arms in a coffin. (Which explains both the vampires pointy teeth and their generally pissy attitude.) Assuming these legends come from the same culture, maybe the idea here is that if the vampire’s head tries to make a break for it, it’ll end up digging its way down, instead of up.
Quincy stabbed him in the heart with a Bowie knife.
Harker cut off his head with a kukri.
Thanks!
It’s to confuse the vampire and keep it in its grave. The idea is that it is then looking toward where it is supposed to be (hell) and away from where it isn’t (the living world.) No cite. Just years of fascination with folklore.
It was frequent practice t o bury folk suspected to be witches/warlocks/vampires/agents of the devil upside down, so that they were face down in the grave, for the same reason. Lovecraft, I believe, wrote a story based on this idea once. It was a fairly standard Lovecraftian “Nephew-of-a-rich-dilettante-inherits-wizard-uncle’s-stuff” setup, but it was pretty good anyway.
If he wakes in his coffin, and starts to dig his way out, he’ll actually be digging downwards.
I considered this, bu in the context of beheading a vampire and turning his head around, I’m afraid it makes no sense.
I’m sure you can see where I’m going with this.