Because in Tarkatan society, biting people is considered very rude. Anyone raised Tarkatan would know this. Mileena, however, is just some slutty bitch who can't keep it in her mouth. After all, she was raised by Kahn to parade around in lingerie.

Probably because the full blood Tarkatans have blades in their arms they'd rather use.
Not to mention that they may not have Mileena's speed and so going in to bite may be too great a risk.

Mileena's hot!

Maybe because she is not a Tarkatan and she has no arm blades.

There is more.

Why the Tarkatan blood to make Mileena?

Shao Kahn could just borrow his DNA and mix along with Kitana's to make a perfect daughter.

Because Tarkartans are easy to control, thats why he wanted her to be part Tarkie.

I like to think of her as MK's Sucubus as long as she keeps that veil on that is lol

I'm not sure how Baraka can open his jaw wide enough to get it around anything. His teeth are a bit longer than Mileena's in this game and MKvsDCU.

what others have said, her mouth and teeth are smaller than other tarkatans, she can actually move her mouth.

Which brings me to question, if Tarkatans can't close their mouth, wouldn't their mouths always be dry?

Actually how do Tarkatans even speak?

Evolution.

Some one needs to make Tarkatan & Shokan anatomy posters, you know like the human body posters in biology classes.

Mileena apparently had blades in her arms when she was created. Her vignette clearly shows them. Perhaps she had them removed so she could blend in better.

But they couldn't chew the gum.....because their mouths don't close.

I gotta admit, that was pretty fuckin funny.

tarkotans cant open their mouths wide enough and they dont have lips yet they speak just fine XD

I'm starting to believe that Tarkatans have a smaller, tiner, functional mouth, or at the very least, some form of vocal equipment in their throats that permits them to enunciate (I came up with this theory after two beers on the challenge tower yesterday), and that they can unhinge their jaws to fit stuff in. There was a time where I could have bought that Baraka was capable of normal speech and just preferred to grin widely all day long, but in recent years - especially since Deception, yeah, no. Cripes, this game's Story mode even has the words just kind of coming out while his jaw barely moves.