Adult "invisible braces" (which are not really braces at all, but clear plastic retainers) are a new technique for adults to obtain the results of braces without wearing braces! This technique, which is effective only for mild to moderate crowding, utilizes a series of retainers (computer generated or lab constructed) that are worn sequentially until the desired correction is achieved.

She's wearing "invisible braces" in one of these two photos. Can you tell which one? It's difficult to tell, isn't it? That's the whole point!