A palatal expander is used primarily to help widen the upper jaw so that both the upper and bottom teeth fit more seamlessly together. There is good evidence showing that an expander can in fact be used whether the patient is still growing or not. It was once thought that this could be accomplished with a growing patient or by having the two halves of the palate separated by surgery. Most often a palatal expander will be followed by braces to align all the teeth to now fit the room that has been newly created.
There is usually expansion that results in a large gap between the patient's two front teeth, though this is not always the case. The gap can close naturally and the teeth may overlap leading to the need for braces. There are two types of expanders, one where the patient has to turn a screw to tighten up the expander. The other alternative is a bionator expander which does not have to be monitored by the patient.
There may be a slight pressure on their teeth, although this may vary from patient to patient, most will feel a slight bit of pressure on their teeth. Over time as the patient continues to turn the expansion screw a space or gap may form between the two front teeth. Some patients might notice a larger space than other who might not notice any space at all. Generally it takes a few days to get used to speaking and eating activities right after receiving the palatial expander. Sometimes patients may experience headaches and pain while wearing palatal expanders just after the screw is turned. Also, they may get a sores on their tongue after coming in contact with the expander's metal bars. There is also increased saliva production for people who wear expanders and some may experience a lisp (difficulty pronouncing the letters T and S).
A narrow upper arch can often lead to irregular alignment and crowding of the teeth when a child ages. It can get much more difficult to correct a narrow arch the older the patient is. If a patient suffers from a severe bilateral maxillary constriction, a palatal expander can be utilized to shape the upper arch.