Well, there’s realism, and then there are the Jack Lambert types. 
Hollywood really does overdo the “perfect grill” these days and they really should leave well enough alone. Not just period peices either; anytime a prison thug or ganster (in modern times), or a dirt poor hillbilly/trailor trash type flashes a brilliant “Ormanesque” set of choppers, the authenticity factor fizzles.
I’ve seen a lot of posts on here using Patricia Arquette as an example of really bad teeth and wondering why an actor wouldn’t get this “fixed”. She has actually addressed this directly (not that she needs to explain her own body choices). Here is the link to the interview:
There is actually a phenomena referred to as “American teeth”. It’s one of the major ways people from other countries can spot tourists from the U. S., by our “perfect, whitened teeth”. That obsession with having perfect, straight teeth is primarily an American thing. Just as people from the states joke about jacked up Brittish teeth, they joke about ours.
I prefer watching t. v. shows from the UK far more than American t. v. because the people look like actual people; overweight, bad teeth, and all. I’m far more captivated by people looking like everyday people rather than overly skinny, over tanned, every hair in place wearing high end designer clothes at all times. Flaws are part of the journey.
Even the zombies in US shows have perfect teeth.
If you’re focussing on their teeth, there’s something wrong with the acting. Or the writing.
You think (ETA: or thought, 9 years ago 
) razors were invented in 1920? Hell, one of the world’s major religions considers *at least *pube and armpit hair removal absolutely mandatory, and has for centuries.
Well, I have teeth similar to Patricia Arquette and Jewel. My dentist told me that it’s a thing found mostly in females. I’ve never felt like I had an ugly smile. My parents couldn’t afford braces when I was a kid (born in '61). When I was an adult it never bothered me enough to do anything about it. It’s just me!
Sorry but you watch smallville it’s so obvious her tooth with brown on it they close up her mouth a lot in it and I noticed the left tooth with but of brown part on it. At first thought it was the screen but it’s her tooth and it bothered me every close up. Actor or non actor teeth with brown etc bother me it’s not about the fame lol
NM. Didn’t notice the dates on the thread
Brings to mind the old actor Terry Thomas, whose front tooth gap was pretty much a trademark. but then, he was British which conveniently explains and excuses any teeth issues. 
Maybe they don’t want fake teeth. Maybe they don’t want to have their mouth worked on. Does the OP (if still around after all these years) enjoy sitting at the dentist’s? I’m sure you wouldn’t enjoy having a cavity filled or your gums cleaned. Now, do you know how painful and labor-intensive braces can be? Are you indifferent to the thought of having someone carve down your natural teeth and cover them with artificial porcelain caps? You think any person on Earth would be nonchalant about sitting through such procedures? I for one wouldn’t want to go through any of these procedures, and my teeth aren’t pretty (I have buck teeth with a visible gap between them and two gaps, one smaller and one larger, in the first case where a permanent tooth didn’t come in and in the second case where a baby tooth that never fell out had to be extracted).
Some of us value being natural. I don’t mean giving up all grooming, merely not making various modifications to your natural body. I don’t like a surgically straight smile. Nor do I like dyed hair, or botox, or fake nails or fake tans. If someone, particularly in an environment like Hollywood, has a good enough body image to not feel the need to undergo every aesthetic procedure on offer out there, then I value that person’s strength of character.
So kudos to those actresses for not bowing down to social pressure and Hollywood standards and leaving their teeth as they are. By my standards, a fake smile would probably not make them look better anyway.
Responding to a zombie of a zombie. Sheesh. Anyway:
I watched every episode of Medium and nearly every episode of Smallville. I didn’t think Arquette was particularly attractive nor unattractive. I thought Kreuk was gorgeous. I’ve since seen Arquette in Severance and Kreuk in Reacher. I’ve never noticed anything unusual about their teeth.
“Distracting”? Come on.
Teeth should be a color so natural that you just don’t even notice them. If you find yourself saying, “My, he has white teeth” they’re too white.