The Palatal Expander is used to widen a narrow upper jaw and, in many cases, helps to acquire more room for crowded upper teeth. The
appliance is bonded into place and typically remains for the better part of 6 months. It is activated once per day for 3 weeks, checked after a month, and activated more as needed until the desired width is attained.
The RPE is used to re-establish a correct bite. Like a hat box, where the lid must fit bigger
than the box base, upper teeth must be broader than lowers all the way around for a correct fit. Otherwise, patients constantly shift to one side or the other (like a mismatched hat box) for a "best
fit" of the bite, often placing stress on the TMJ on one side. This stress may or may not cause problems until later in life. Speech and chewing is somewhat more challenging when the
appliance is first placed. A space between the upper two front teeth will often appear as widening occours, but this space spontaneously will close to pre-expansion conditions within a few weeks. This appliance is well
tolerated by the majority of patients. It is especially important to realize that the expansion of the palate is possible easily and non-surgically from about
age 7 until the age of 12-15, and is usually very difficult thereafter.
To see how this appliance works first hand click the corresponding link
below to see the video. It may be benificial to watch in 128k mode even if you are on a slower dial-up modem for clarity, although it will take longer to download. 
