It is advisable for children with a seriously misaligned jaw or with an extremely small jaw to be screened at a young age (between 7 and 9 years old) in order to determine whether early orthodontic pre-treatment is recommended. It is often advisable to carry out orthodontic treatment in two phases for more serious jaw misalignment. This will allow for an optimal use of the growth phase to support the correction of the misalignment. The first phase takes place during the early stages of transition from milk teeth to permanent teeth; the second phase takes place once the transition is complete. Excessive jaw misalignment in young children can be treated with removable plates which are supported by growth. This functional orthodontic treatment can be used to correct crossbite, open bite, overbite and underbite. With good cooperation from the child, the treatment lasts on average one year. Once the malocclusion has been treated, it is important to stabilise the results until the full transition to permanent teeth has been completed. After the transition to permanent teeth, can we see whether orthodontic treatment is necessary. If so, it will often be less extensive and quicker.