All these ancient skulls have perfectly straight teeth, despite almost certainly never sporting braces. According to the fossil record, straight teeth and third molars (or wisdom teeth) were common among ancient humans. The dental dilemmas that fuel the demand for braces and wisdom teeth extractions today appear to be recent developments. Scientists hypothesize that the ancestors of modern humans lived a subsistence lifestyle and had to work hard to make their food digestible, leading to larger jaws and teeth overall. As humans began to use tools and fire to cook and prepare food, and later began to process and refine their food, their jaws gradually decreased in size, leading to dental crowding and crooked teeth. It is estimated that between 30 to 60% of people today experience some level of tooth crowding, though this varies across global populations. To prevent tooth crowding, lifestyle changes and orthodontics may be beneficial.