The most common and most likely answer to this crossword clue is the 9 letter word FORETEETH
I've seen this crossword clue in Financial Times
F
O
R
E
T
E
E
T
H
More clues leading to the result FORETEETH
Buddy explains!
The straight part
We know that "They come between canines and have a sharp bite" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they come between canines and have a sharp bite = foreteeth.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.