Orthodontics deals primarily with the diagnosis, prevention and correction of malpositioned teeth and the jaws. Malocclusion is not a disease, but abnormal alignment of the teeth and the way the upper and lower teeth fit together. The prevalence of malocclusion varies, but using orthodontic treatment indices, which categorize malocclusions in terms of severity, it can be said that nearly 30% of the population present with malocclusions severe enough to benefit from orthodontic treatment. Orthodontic treatments like braces help move teeth that are crooked or that do not fit together right. By fixing these problems, orthodontics can also help keep your mouth healthy. Crooked teeth can be harder to clean, putting you at risk for cavities and gum disease.