[The growth of the skull and its importance for the occlusal conditions in Down's disease].

The teleradiographs and study casts of 68 patients with Down's disease were compared with those of 102 students. Pseudoprognathism, cross-bite and open bite were strikingly more frequent in the patients with Down's disease than in the students. The success of orthodontic treatment is very uncertain in patients with Down's disease. Mandibular prognathism needs in most cases surgical treatment. An open bite will be improved only if the position of the tongue is changed. Improvement of a cross-bite may be achieved by early expansion of the maxillae. In certain cases, normalization is accomplished. It is possible to reach considerable inprovements in patients showing a few or no occlusal surfaces though normal conditions cannot be established.