Malocclusion is the misalignment of the human dentition and craniofacial complex. Orthodontic treatment to correct this is quite common in modern Western contexts, and has variable prevalence in other areas as well. The archaeological record stands in stark contrast, with most past humans having teeth that align well. What could cause different populations to exhibit these characteristics? There is evidence in both modern and archaeological contexts that levels of dietary masticatory stimulation during development greatly change occlusal characteristics. Additional bite force and number of chewing cycles creates a flatter Curve of Spee, greater subnasal prognathism, and increased progressive tooth wear, which together facilitate better occlusion. With dietary changes such as those seen in the Industrial Revolution, the comparatively softer food creates widespread malocclusion in the effected population. These ideas are explored in terms of archaeological and contemporary case studies. Health transitions such as this commonly coincide with major changes to subsistence style, and can help biological anthropologists better understand the experiences of those in the past.