A diastema is a gap between central incisors . Many celebrities are famous for their midline diastema like zac efron. Diastemas are extremely common, especially among children. In fact, up to 97% of children have diastemas, and that number significantly decreases as children grow and these spaces close up naturally. If a diastema remains after the eruption of adult teeth, it will become permanent and can only be corrected with professional treatment.