First off, straight teeth contribute to a nicer smile. Many studies have shown that an attractive smile boosts self-esteem which is important at any age. For children, the development of a positive self-image can carry forward throughout life and contribute to future success. For adults, self-esteem is critically important in many professional settings and social situations.
As important as appearance can be, the benefit of braces goes beyond just esthetics. Straight teeth help an individual more effectively bite, chew, and even speak. It may come as a surprise that straight teeth contribute to healthy teeth and gums. Straighter teeth are easier to brush, clean, and floss! The ability to take better care of the teeth through oral hygiene also helps prevent future cavities and periodontal disease. This latter problem is of particular concern because over time it can lead to destruction of the bone that holds the teeth in place.