Structural dentofacial variations in maxilla expansion

The control of vertical dimension is important in those subjects who need a correction of the maxillary transversal diameters, in order to project a correct therapeutical plan and not to make worse an eventual contemporary long-face. This research intends to consider the vertical dimension changes of the cranio-facial middle third caused by palatal expansion, in relation to technique and patient's age.

We have compared orthodontic-orthopedic expansion both with elastic appliances ("w" expansion palatal arch), stiff ones (Hyrax-type appliance) and surgically assisted expansion which combines the action of Hyrax-type appliance with a bilateral corticotomy of zygomatic buttress. Among treatments of this kind which have been carried out in Odontological Clinic of University of Verona, we have selected three groups of subjects who have been treated with orthopedic expansion the first one in infantile age, the second one in adult age, and the third one with surgically assisted expansion. At the end of the treatment, we have evaluated dimension changes of the cranio-facial third middle caused by therapy, with the aid of a cephalometric analysis made on purpose.

The results obtained are similar in the case of orthopedic expansion in young people and in surgically assisted expansion, while the increase of vertical dimension caused by the orthopedics expansion in grown-up people is more substantial.

Considering these data, it appears that the surgically assisted expansion is more effectual and physiological for the correction of transversal deficiencies of maxilla in grown-up people.