Mandibular repositioning appliance (MRA)

A mandibular repositioning appliance (MRA) is a dental appliance. It is similar to a gum shield.

An MRA is used to treat snoring and mild to moderate sleep apnoea (when your breathing stops and starts while you sleep).

It is worn in your mouth when you are asleep.

An MRA works by holding the lower jaw forward and moving the tongue forward to clear the airway during sleeping. This can reduce or stop sleep apnoea.

It also increases the amount of oxygen getting into your body and usually reduces breathing noises and snoring.

It's made of soft material and should not have any effect on moving your jaw.

Wearing your MRA

The appliance needs to be worn for as long as possible at night, ideally for 5 to 6 hours.

It will take time to get used to the MRA. Do not try to sleep with it immediately.

Take time to get used to it for increasing periods of time when you are not thinking about it. This could be when you are watching TV or reading.

Pain when wearing the MRA

Some people have slight discomfort where the teeth meets the gums (gum margin) when they are wearing the MRA.

This can be helped by careful adjustment (you can carefully use a nail file or emery paper).  This discomfort can happen sometimes as the gums can swell up if traumatised or become inflamed due to poor cleaning, and having dental plaque.

The muscles involved in clenching the teeth might ache at first, but this should settle within a few days.

The main area of discomfort is usually the jaw joint immediately in front of the ear, which can become very painful.

The appliance can also be adjusted by your own dentist if necessary.

If you feel major discomfort, remove the MRA and contact the dental sleep department

If your teeth ache after wearing the appliance, it's likely that you are grinding your teeth. This will be made worse by wearing the appliance. If you cannot overcome this, you might choose not to wear the appliance any more.

Looking after your MRA


Daily soaking in a special cleaner will make the appliance last longer. A cleaner like Retainer Brite® can be used each day. It is available to buy online and can be ordered in larger pharmacies.

You can also use a fizzy denture cleaner (such as Polident® or Steradent) once a month.

Soak the appliance for 20 minutes in cold water, rinse thoroughly and store it either dry or in plain water.


If used regularly, the appliance should last about 2 years. After this time, it might be hard, discoloured and less functional, and might need to be replaced.

As you have been discharged from our care, if you need a new appliance, you will need to ask your GP (not your dentist) to send us a letter asking for a replacement.

A follow-up appointment is not normally needed. However, if you have any problems, please contact us for an appointment.

Do not worry if a hole appears in the appliance as it is the mechanical integrity of the appliance which is important, not the suction effect of the appliance against the teeth.

Looking after your teeth

Dental check-ups

It is important that you have a healthy mouth to minimise the chance of the MRA doing you any harm. You should have regular dental check-ups to maintain healthy teeth and gums.

If you get a new filling or a crown, the dentist can adjust the appliance at the same time to allow for the change in shape.

Cleaning your teeth

You must make sure that your teeth are carefully cleaned before putting the MRA in your mouth. With good dental care the appliance will not affect your teeth.

Any gum problem or tooth decay could be made worse as the appliance covers the teeth and gums and saliva cannot reach them.

If you're having problems

Over a long period of time, it is possible for the lower jaw position to change and sit forward of its original position. If you have any concerns or notice any change in the way the teeth meet (the bite), stop wearing the appliance and contact the dental sleep department

It might only take a discussion and reassurance before you can wear it again. 

If the appliance is not helping you, you should stop wearing it and report this to the consultant looking after your sleep medicine disorder.

Resource number: 3742/VER7
Last reviewed: October 2021
Next review due: October 2024

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