Removable appliances -- the Schwarz with occlusal coverage comes immediately to mind -- correct crossbites by exerting a slow constant pressure on the teeth and bone. An alternative approach that has shown to be equally as effective is the use of rapid expansion to open the mid-palatal suture. The Hyrax High Palate Rapid Palate Expander can be used successfully in patients with mild-to-moderate transverse constriction when they are in the late mixed or early permanent dentition. In this case, sutures are presumably still patent -- and the appliance works best when the crossbite is caused by a deficiency of the maxillary apical base.

Rapid expansion is obtained over a two-to-three week period by means of turning the expansion screw once a day. This creates enough pressure to separate the mid-palatal suture and the appliance is then worn for another three to five months to allow time for osseous healing. Framework is all-stainless metal. The expansion screw is positioned high in the palate for greater comfort. Bands are placed on the first molars and rests are bonded to the occlusal surface of the primary molars. Path of insertion problems, e.g. that which occurs when four bands are used, are eliminated. Extra heavy support wires are also used to prevent the appliance from flexing as pressure is applied. If you find that the posterior crossbite is locked due to a deep bite or tight intercuspation, it is recommend that a lower occlusal splint be placed temporarily to expedite treatment -- without affecting the mandibular dentition.