Figure 10: Symptoms and signs of importance for avoiding resorption during orthodontic treatment. (a and b) exemplify that it is important to diagnose abnormal resorption patterns in the primary dentition, often leading to resorption in the permanent dentition. Radiographs (c and d) demonstrate how the first molar with normal root length (c) can change to a short distal root (d) without previous orthodontic treatment. A condition like this and conditions shown in Figure 6 are morphological characteristics that should be a warning sign for orthodontists, who are planning treatment with fixed appliance. The three figures to the right are shown with permission from orthodontist, Izabella Vest Hansen. The figures demonstrate a patient with ectodermal signs in hair, skin, and molars, which should be diagnosed before applying orthodontic treatment. The maxillary first molar roots have nearly completely resorbed without orthodontic treatment. The mandibular first molar is secondarily retained, indicating an abnormal functioning of the periodontal membrane