AC – How to use maxillary expander

orthodonticsmid palatal suture skeleton mid palatal suture
The Rapid Maxillary Expansion functions to expand the width of the upper arch. We often use them to correct cross bites in a child by pushing the upper maxillary sutures outwards with the expander (we can’t do this in adults freely as the sutures turn into hard bone, which makes it impossible without the help of surgery).

In the first few days it is normal to experience some
discomfort, paracetamol will help reduce this. Wax can be used to relieve any irritation caused by the appliance. To use wax, pinch off a small amount and roll into a ball, press onto the appliance after it has been dried. Remove the wax for eating, drinking and tooth brushing.


Taking care of your appliance

As your appliance is cemented to your back teeth care must be taken when eating. It is important to avoid sticky, hard foods such as toffees, minties, roll ups, etc. You should also avoid cold foods such as ice cream, ice poles and ice blocks; the cement used on your appliance becomes loose when exposed to such products.

In the event that the appliance becomes loose, bring your chart over to our surgery so we will be able to reset the appliance for you and re-cement it back.



Clean your appliance and teeth with a toothbrush and toothpaste after eating and drinking. If you are unable to brush, rinse your mouth with water.


Progressive Treatment

In some instances a gap may develop between the top front teeth. Don’t be concerned, as the gap will close. We will check your appliance at regular intervals. Your first appointment will be in 4 weeks at which time we will assess the expansion and monitor your cleaning.


Turning the Screw

Either you, your mum or dad, can turn the expansion screw with the wire “Key” we gave you at your appointment.

Put the key into the small hole that is visible in the middle of the expansion screw/appliance. Turn it away from your front teeth towards the back of your mouth (following where the arrow is on the device). Turn the key as far as it will go until it stops before taking the key out- that way, the next hole will be visible and ready for the next time you have to activate the appliance.

If you are turning this by yourself, do it in front of a mirror in your bathroom, have your cellphone ready (for the LED flashlight) or a torch.

For mums and dads, to help your kids turn, let them lie on your lap as if they are seeing us in the dental char, a good LED flashlight, and turn the appliance.


We have attached a chart to this sheet.

Use this chart to keep track of the number of turns for each day and the total turns since we first gave you the appliance. Please remember to bring this chart with you at every appointment! Keep it on a wall somewhere handy so you can record the results of the expansion.

expander diagram

Download the PDF of the extra chart by clicking here.

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