Mila Kunis might know a little bit about having face shapes that are as long as they are wide. Round visages might also include short, soft jawlines. If you share these features, adding some angles would be ideal to giving your face a more structured look.
Blunt bangs cut above the brow give the illusion of face length. If you have them any longer than that, you might be accentuating the widest part of the face, thereby defining the roundness of the face. Another great way to help create facial balance is by getting soft, textured, sideswept fringe. This helps to widen the forehead, add angular shape and to soften the look of wider cheeks.
Source : http://www.eonline.com/news/631280/how-to-get-the-best-bangs-for-your-face-shape