Bilateral posterior crossbites are typically the result of an underdeveloped maxilla. Reasons for this occurance may include abnormal tongue posture, irregular swallowing pattern, obstructed airway caused by allergies. When a patient presents a bilateral crossbite, a Schwarz Appliance with Posterior Occlusal Coverage can be used. Occlusal coverage opens the vertical and is typically finished flat to allow for the quick resolution of the crossbite -- without affecting the opposing dentition. By wrapping the occlusal acrylic over the buccal cusp tips, tipping of the dentition is kept to a minimum. Turning the expansion screw one-quarter turn a week exerts a slow, constant pressure on the teeth and bone. This arch development moves the posterior segments buccally out of crossbite and, in the process, drops a high-vaulted palate opening the nasal airway. Once the crossbite is corrected, the occlusal coverage should be removed -- this allowing the patient to function into a normal occlusion. Note: As the high vault drops with expansion of the arch, adjustment of the acrylic on the palatal side of the appliance may be necessary to ensure proper seating of the appliance.

IMPORTANT: Recognition and treatment of a posterior crossbite early in a child’s development is essential. When left untreated, it can lead to numerous serious medical complications, e.g. Class II skeletal deformity, TMJ dysfunction, and airway obstruction.