The most common and most likely answer to this crossword clue is the 8 letter word PEARLIES
I've seen this crossword clue in The Times
P
E
A
R
L
I
E
S
More clues leading to the result PEARLIES
Buddy explains!

The straight part
We know that "teeth" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case teeth = pearlies.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.
What does PEARLIES mean?
PEARLIES noun- A pale greyish white colour, tinted with blue.
- (especially in plural) A tooth.