[Changes in the dental arch due to obligatory early extraction of first permanent molars].

The first permanent molars are the mo frequently extracted teeth due to caries. Early loss of these teeth which are known as "the ke of the occlusion" may lead to rotations, migrations, and elongations of the other teeth in the dental arches, and finally may cause occlusal disorders. This research is conducted on the patient whose first permanent molars need to be extracted due to profound caries and unrestorab material loss. By means of the lateral and panoramic radiographs taken just before the extraction and one year later, the local changes in the extraction and non-extraction segments are compared.