Hiring teens for the jobs for 16 year olds that your company has is a very different ballgame from any other hiring that you might have been doing for years. Here usually you cannot set the same criteria in terms of qualification and have to rely on much more advanced selection criterion that can bring the right person to you. One of the traits linked to young age is unpredictability and more often than not you will come across it in most of your prospective candidates who are teens. You will have to build in a lot more contingency in your hiring practices.
Even if micromanagement is not your style, you will have to make sure that more than usual guidance and check is available for these job roles not only because of the young age and inexperience of such employees but also to ensure right learning and a clear understanding of what is expected from the employees at all stages in any situations.
Many personality traits that we assume to be present in a person who has reached adulthood will be missing more often than not in teens so you will need to be more clear and detailed about other skills that you can use as the basis of selection.