Palatal expanders create more space in a child's mouth by gradually widening the upper jaw. Although this may sound scary, it's really quite easy — both to do and to tolerate. That's because the upper jaw actually develops as two separate halves that don't completely fuse together until sometime after puberty. Before that happens, the two bones can gently be separated and stabilized over a period of several months.
 

The three situations that most commonly call for maxillary expansion are:
 

Crossbite — When a child's upper jaw is too narrow to fit correctly with the lower jaw, the back top teeth will bite inside of the lower teeth instead of outside. This can be corrected by expanding the upper jaw.

Crowding — Even before all of a child's permanent (adult) teeth come in, we can tell when there will not be enough room to accommodate them. Widening the upper jaw can create the necessary space without the need for tooth extractions.
 

Impacted Teeth — When a tooth that hasn't come in (erupted) yet and is blocked by other teeth, widening the upper jaw can allow it to erupt into proper position on its own. This most often happens with canine or eye teeth — the pointier ones located directly under the eyes.

Expanding the upper jaw has other benefits: It can broaden the smile in an aesthetically pleasing way, it can limit the number of teeth that need to be removed to create space and can also improve breathing. And it can shorten overall orthodontic treatment time (the amount of time your child will need to wear braces).