Most of us grew up hearing that “crooked teeth run in the family”, yet modern evidence paints a broader picture. Studies show that breathing through the mouth, especially in childhood, can narrow the dental arches and shorten the mandible, leaving little room for the last molars to erupt. Put simply, an open mouth today may translate to an impacted wisdom tooth tomorrow. This article seeks to explore what the current science tells us and how that knowledge applies to everyday Australians weighing up wisdom teeth removal cost or wondering whether the problem can be prevented in the first place.