Expanding Your Palate
If you are an artist, your palate may be very messy and colorful. If you are a gourmand, then your palate describes your appreciation of smell and taste. Anatomically, your palate is the roof of your mouth.
Some people have a narrow palate for a variety of reasons:
Depending on how the narrow palate formed, the treatment will include some intervention such as surgery for a cleft or a habit treatment. But almost every treatment will include an appliance to widen the narrow palate if there is a cross bite.
Crossbites are the upper teeth biting inside the lower teeth. See this discussion of crossbites for more details of the various kinds of crossbites.
Although both sides can be in crossbite, most crossbites occur only on one side, a unilateral crossbite. These cause the lower jaw to swing toward one side so the lower midline is moved toward the crossbite side. Because the lower jaw is made out of one bone, it is harder to change its shape. The upper jaw is made of two bones that can be moved more easily and effectively. An appliance to widen the upper jaw usually works in 6 weeks and then stays as a retainer for another 4 months. I like to use an expander that covers the posterior teeth because it helps prevent the downward movement that is usually found with expansion of the upper jaw due to biting force.
This expander is bonded to the teeth to seal out plaque and to get a very firm hold on the teeth so that they do not tip and they move the bones apart more effectively.
This bonded palatal expander moves the jaw bones relatively rapidly compared with a removable one that takes many months to widen the upper teeth (and that mostly moves the teeth rather than the bones) so it is called a Rapid Palatal Expander or RPE for short.
A RPE will almost always spread the maxilla or upper jaw bones enough to make a temporary space between the upper front incisors. The gingiva or gums are full of stretchy collegen fibers that connect the teeth and act like rubber bands to close the space between the front teeth rather quickly.
After correction of the crossbite, the lower jaw will move back to center the midline and the non-crossbite side will move backwards to match the joint on the now corrected crossbite side. This is according to: Changes in condylar position and occlusion associated with maxillary expansion for correction of functional unilateral posterior crossbite in American Journal of Orthodontics and Dentofacial Orthopedics, Volume 111, Issue 4, Pages 410-418 by K. Hesse, J. årtun, D. Joondeph, D. Kennedy.
What this tells me is that because the non-crossbite side cannot easily move backward (due to the structure of the joint), the other side has to move out of position downward and forward. Once the upper jaw is expanded to the correct width, the lower jaw can resume the correct position and the corrected side joint will move up and back to match the crossbite side.
Overall, the RPE is a relatively quick and effective way to expand your palate for both unilateral and bilateral posterior crossbites.