A palatal expansion device is sometimes referred to as an RPE, a Haas appliance or a Hyrax appliance. It is typically used to expand the upper laterally, by separation of the mid palatal suture so the upper and the lower teeth fit together better. The use of the appliance is more common in children before closure of the mid palatal suture as occurred, but it has been successfully used in older adolescents and adults; the effects of expansion in these last two groups has been reported to be slightly more uncomfortable. Also, depending upon the amount of expansion, adults may require surgical separation of the top jaw.
The expansion process usually creates extra spacing in the top arch, which can be beneficial if more space was required for the alignment of crowded teeth. Some expanders require the patient to turn an activation screw daily; others are activated by the orthodontist.
There are many types of expanders available. Some are fixed and cemented to the teeth, some are removable by the patient and now some are attached to Temporary Anchorage Devices (TADs or mini implants).
There are relative advantages and disadvantages for each technique and Dr. Hight will review these with you during your treatment consultation.