When looking more closely at the power of your mouth, another trick is for you to take the time to smile if you want a guy to approach you. Specifically, the bigger your smile is, the more attractive that you'll appear to others, as discussed in Cognition and Emotion.
So right off the bat, smiling can help you to appear more physically alluring and appealing to the opposite sex. To that end, a study in Psychological Science revealed that people have a higher preference for and gravitate more towards smiling faces over non-smiling faces. And while it's not too surprising that having white teeth rather than yellowing teeth is also viewed as highly appealing, what may surprise you is that the quality of a person's teeth is actually considered to be representative of his or her ability to be a good mate, as noted in PLOS One.
In a word, your teeth clue others in regarding your overall health and well-being, so having pearly whites sends a signal to men that you have true dating and mating potential.