[Rapid palatal expansion for the treatment of maxillary constriction].
Rapid Palatal Expansion (RPE) has become a classical technique yielding a morphological expansion similar to that obtained with bone distraction. This non-surgical approach based on the application of dental bands take advantage of incomplete closure of facial sutures in children, especially the palatal suture, which opens under the pressure of the appliance. Semi-rapid expansion, 0.5 mm expansion per day for 15 days, is a compromise between pain and efficiency. The morphological expansion assures correction of maxillary width, even when only two bands are used. The etiology is often difficult to determine but interestingly, mouth breathing is associated in a large number of patients. The consequences of this ventilatory dysfunction are complex and involve increased posterior rotation, maxillary and mandibular developmental disorders, sleeping disorders and nocturnal enuresis behavior and at the dental level a characteristic open bite. RPE is not a perfect solution, but it does allow recovery of transversal growth by mechanical enlargement. Palatal expansion also widens the nasal cavity which becomes more permeable to airflow. Nasal breathing becomes easier but still requires retraining. Spectacular effects on dento-facial development can be observed, including closure of open bite and reorientation of mandibular growth. Stability is particularly dependent on the success of functional correction. A global approach, considering both the morphological and functional aspects of the problem is required to achieve harmonious and stable correction. Early treatment (7-8 Years old) provides excellent results. RPE can be performed at an older age (13 to 14) but with less spectacular effects on growth.