Considering that the 'space suit' is biomechanical in nature I have no problem with it having teeth.
My trousers aren't biomechanical but the zip has teeth (which is why it's not wise to fasten in haste).
As a side note the film seems to revolve around people making giant assumptions which are taken as fact.
They are there because a glyph in some pictorial depictions (but not all of them) shows a pattern of dots which are interpreted as a star map (no not a map, an invitation) but where's the evidence?
They could just be dots and the aliens being there could be a cosmic coincidence.
Then the Captain pulls the idea it's a weapons research base out of his hat and the film runs with that.
Suddenly Shaw proclaims that we did something wrong and our creators (another lucky guess?) changed their minds about us and wanted to kill us.
There is no evidence for any of this in the film other than what is said by these very unprofessional professionals.
It could be that we are an unfinished project.
Perhaps we are parts for a machine or maybe we are their successors and we need further upgrading (which is what the goo is meant for).
Maybe the goo in the shrine wasn't meant for us or was meant for us but because they went in with their suits on or with the helmets off the crew screwed up the engineers Christmas present for us.
All wild stabs in the dark but it makes as much sense as those announced by the characters in the film.
At no point does anyone ask Shaw where this information is coming from or speculate differently.
She's the expert so what she says must be accurate right?.
Vickers is only skeptical about what she says until the alien complex is revealed to be alien and then she never questions Shaw's ideas again.
And she isn't even a scientist, she's some idiot who thinks half a billion miles is an interstellar distance.