From a myofunctional therapist’s perspective, a palatal expansion device is a good thing. When the dental arch (the “U” shape that contains the top teeth) has been widened, there is ample room for the tongue to rest, swallow and speak.
The device is typically put on prior to braces to widen the upper dental arch so the top and bottom teeth match (they interdigitate; the cusps fit into the grooves). The lower dental arch can be widened as well, it’s happens less common, however.
The presence of a palatal device usurps any lingual-palatal swallowing or speech therapy. Therapy is put on hold for six to eight months. Once the device is removed the palatal space can easily accommodate the tongue to do its stabilization-mobilization maneuvers.
There are several types of palatal expansion devices. One of the most popular is the Rapid Palatal Expander. It attaches from side to side on the top teeth, and has a turn-key; your orthodontist will fill you in as to how to use the key and how often.
Another, is the Quad Helix, sometimes called a “W” Appliance. It’s can be fixed or removable, and is made of a stainless-steel wire that contours around the perimeter of the dental arch. Both types can make speaking and swallowing difficult. Do not be surprised if your /s/ speech sound is distorted. It will go back to a normal /s/ after the device is removed.
Please Note: A palatal expansion device is different from a reminder devise. A reminder appliance is used by some dentists to extinguish thumb or finger sucking, tongue sucking, or a tongue thrust swallow. The reminder appliance (sometimes punitive) is typically inserted within the dental arch in the area of the alveolar ridge (the bumpy part behind the top teeth), pretty much in the location where the tongue needs to learn to rest and function.