You might think that having a great smile is all it takes to be attractive, but science has proven otherwise. While a great smile is certainly a plus, there are many other factors that go into making someone less attractive:
Bad breath (think onions, garlic, or cigarette smoke)
Bad skin (acne, rashes)
Messy hair (unkempt or oily)
Body odor (sweaty body parts)
Bad teeth
Poor posture and body language (hunched shoulders, crossed arms) convey weakness and lack of confidence