Often a too narrow upper jaw creates problems such as tooth crowding, a cross-bite and mouth-breathing. Tooth extractions can make place for the remaining teeth, but may lead to a dished-in, prematurely aged face. A smile showing a wide dental arch, with little space between the cheek and the teeth, is more attractive. "Trans Palatal Distraction" is a technique by which the upper jaw is surgically weakened at the buttress areas and widened by an expansion device that is fixed in the palate. Due to this bone born technique the maxilla regains its initial strength after the widening. In this way, the cross-bite is corrected and the space that is created between the central incisors is used to align other teeth. It is recommended to inform the patient that a space between the incisors will occur. (Between 4mm and 10mm). After bone regeneration, due to distraction osteogenesis, all teeth will be gently aligned by orthodontic treatment.