"If your child breathes through mouth more than his nose, it may seem like a harmless habit, but it can have a considerable impact on health and attention spans of children. By just getting the child to have enough sleep can dramatically improve a child's behavior and focus. If your child breathes through the mouth while sleeping, it allows the tongue to drop down from the usual resting place, i.e. roof of the mouth and slide back into the throat, blocking the airway. This causes snoring and sleep apnea, resulting in irregular sleep patterns, adverse behavioral, ADHD and cognitive development symptoms. "