When you think of a perfect smile, chances are you think of a wide grin with gleaming, straight and perfectly-aligned teeth, but new research suggests that’s not entirely the case. A recent study by researchers at the University of Minnesota discovered that what others perceive as a “successful smile” has less to do with how much of your teeth you show and more to do with facial symmetry and balance.

Published recently in the PLOS ONE journal, researchers throughout the course of the study showed a series of 3D computer generated faces to 802 participants. Using variations in the size and symmetry of the smile and angle of the mouth, each face had a slightly different expression. Participants then rated the smiles on how pleasant, effective and genuine each face appeared when smiling and what they thought the emotional intent behind each smile was.

The study found that the smile that was rated most pleasant, genuine and effective—or the most “successful smile”—had a perfect balance of smile length, an ideal mouth angle and how much teeth were barred. Contrary to popular belief, the biggest smile didn’t equal the best smile.The right combination was dubbed the “sweet spot,” and other smiles that showed a sync of the left and right side of the face were also rated highly. Unsuccessful smiles were those that had high angles on each side, were too broad and showed too many teeth and were rated as “fake” or “creepy.” Unsurprisingly, smaller smiles with smaller angles were the most likely to be thought to show “contempt.”