Purpose
Widen upper jaw
Best age
Still growing
Helps
Crowding and crossbite
Device
Fixed or removable
Overview
A palatal expander gently widens the upper jaw. In children and teenagers the two halves of the upper jaw are not fully joined, so steady pressure can guide them apart.
Expansion can create space for crowded teeth and help correct a crossbite, where upper teeth bite inside the lower ones. It is most effective while the jaw is still growing.
What to know
- Widens a narrow upper jaw
- Can make room for crowded teeth
- Helps correct some crossbites
- Works best in growing children and teens
- Often used before or with braces
Common questions
Does expansion hurt?
You may feel pressure or tightness after adjustments, which settles.
How is the expander adjusted?
A small key is used to turn it a tiny amount, as your dentist shows you.
Will I have a gap between my teeth?
A space can appear at the front and usually closes again.
Can adults have expansion?
It is harder once growth stops and may need a surgical approach.
How long is it worn?
Often a few weeks to widen, then a holding period.
Related topics
Crowded & crooked teeth
When teeth overlap or twist because there is not enough room in the jaw.
Why orthodontics?
Straightening teeth can improve how your bite works, looks and stays clean.
Airway & dental development
How the jaws and airway grow can affect breathing and tooth position.
Bite problems (malocclusion)
When upper and lower teeth do not meet the way they ideally should.
Dr Rick Iskandar · Reviewed June 2026