Clear plastic trays look alike, so people often mix them up. A retainer, a night guard and a sleep appliance can all sit in your mouth overnight, and each has a different job.
- Retainer: holds your teeth where braces or aligners left them.
- Night guard (occlusal splint): protects your teeth if you grind or clench (healthdirect, teeth grinding).
- Sleep appliance: an option for snoring or sleep apnoea, after a doctor has made the diagnosis (ADA Policy 6.7).
Which device is which?
A retainer follows tooth straightening. Without one, teeth tend to drift back towards where they started (Martin et al., 2023).
A night guard is a custom-made mouthguard. Healthdirect lists it, along with stress management and relaxation, among the ways to manage grinding (healthdirect, teeth grinding).
A sleep appliance is a custom oral device fitted by a dentist. It comes after a medical diagnosis, and your doctor stays involved to check it’s working (ADA Policy 6.7; healthdirect, sleep apnoea).
Where do you get each one?
Your dentist or orthodontist makes a retainer. If yours is lost, cracked or too tight, call us soon, since teeth can start to move once it’s out of use (Martin et al., 2023). After a check of your teeth, we can arrange a replacement where one suits you.
For a night guard, start with an assessment. Not everyone who grinds needs treatment, and some people need help with the cause, such as stress (healthdirect, teeth grinding). Read about our custom bite protection.
For a sleep appliance, start with your GP. They arrange the diagnosis, which can include an overnight sleep study. Your dentist then makes and reviews the appliance (healthdirect, sleep apnoea; ADA Policy 6.7).
If your retainer breaks
- Keep every piece and book a visit promptly.
- Don’t bend, glue or reshape it yourself.
- If a fixed wire comes loose, avoid biting on it.
- Bring the old retainer to your appointment.
Signs that you might be grinding
Sore jaw muscles in the morning, headaches, worn teeth, or a partner who hears grinding can all be signs (healthdirect, teeth grinding).
People who grind in their sleep may be more likely to have other sleep disorders, such as sleep apnoea. If we see signs, we may suggest a check with your doctor (healthdirect, teeth grinding).
Sources
- healthdirect (Australian Government). Teeth grinding (bruxism)
- Australian Dental Association. Policy Statement 6.7 – Use of Dental Appliances to Treat Sleep-Disordered Breathing (reviewed June 2025)
- Martin C, et al. Retention procedures for stabilising tooth position after treatment with orthodontic braces. Cochrane Database of Systematic Reviews. 2023. PubMed 37219527
- healthdirect (Australian Government). Obstructive sleep apnoea
Where To Read Next
Want more on this topic? This page goes further, and it lists questions to bring to your visit.
Airway, Sleep & Breathing Guide
