Palate expanders · growth guidance
Palatal Expansion, Without the Mystery
A palate expander gently widens a narrow upper jaw while a child is still growing. Here is how it works, what the research actually measures, and how to tell whether it might help your child. Expansion is planned and fitted at our Beaconsfield clinic.
Clinically reviewed by Dr Sofia Monter, general dentist with additional orthodontic training · Reviewed October 2026
Weekend appointments: orthodontics and airway checks now run on Saturdays and Sundays.
At a Glance
- Best timing: childhood, while the seam in the palate is still responsive.
- Active widening: usually a few weeks, then the appliance stays in place for some months.
- What it changes: the width of the upper jaw and the floor of the nose.
- What it is not: a stand-alone treatment for sleep apnoea.
- How it feels: pressure or soreness over the first few turns that usually eases.
- Typical cost: most orthodontic and airway treatments here cost $4,000 to $9,750, with an approximate quote at your free consultation.
Why the Palate Matters for Breathing
The roof of the mouth and the floor of the nose are the same piece of bone. When the upper jaw grows narrow, the nasal passages above it are narrower too, and the tongue has less room to rest where it belongs, against the palate. Children with this pattern are more often mouth breathers, and mouth breathing in childhood is in turn associated with changes in how the face and jaws develop (Harari et al., 2010; Huang & Guilleminault, 2013).
Widening a narrow upper jaw therefore does two jobs at once. It makes room for the adult teeth, and it widens the floor of the nose while the bone is still able to change.
This page is part of our orthodontics in Beaconsfield guide, which explains how we plan every case around breathing and jaw development.
How an Expander Actually Works
The two halves of a child’s upper jaw meet at a seam in the middle of the palate. An expander is a small custom appliance fixed to the back teeth with a screw across that seam. A parent turns the screw a tiny amount at home, on a schedule we set, and the gentle steady pressure encourages the two halves to move apart by a fraction of a millimetre at a time.
The active widening usually takes a few weeks. The appliance then stays in place for some months doing quiet work: holding the new width while fresh bone fills in the seam and makes the change stable. A temporary gap between the front teeth often appears during expansion. It looks alarming and is actually the clearest sign the jaw itself is widening rather than the teeth simply tipping. It closes on its own.
What Does the Research Show?
Imaging studies have measured wider nasal airway dimensions after rapid maxillary expansion, with changes maintained at follow-up in many cases (Baratieri et al., 2011). In children with obstructive sleep apnoea and a narrow upper jaw, several reviews have linked expansion with lower sleep-study scores (Camacho et al., 2017; Yu K et al., 2026). Other reviews rate that evidence as low certainty, because most of the studies had no comparison group, and one analysis found expansion on its own did not reliably improve sleep-study results compared with no treatment (Bucci et al., 2023; Yu M et al., 2023).
Those findings deserve their fine print, and we will always give it to you. The studies describe selected children, usually those with a genuinely narrow palate, and results vary between individuals. Expansion is a treatment for a narrow upper jaw. It is never a stand-alone treatment for a sleep disorder, and we do not diagnose sleep disorders: where a child’s history suggests one, we refer to a GP or paediatric sleep physician and work alongside them (Marcus et al., 2012).
Who It Can Help, and Who It Cannot
- Growing children with a narrow palate or crossbite. The ideal candidates. The mid-palate seam is still responsive, so modest forces achieve true skeletal change.
- Teens. Possible, assessed individually. The seam matures at different ages in different people.
- Adults. The seam has usually fused. Conventional expanders alone are unlikely to widen an adult jaw, and pretending otherwise would waste your money. Effective adult options exist, including surgically assisted expansion under specialist care, and we refer honestly when that is the right path.
Living With an Expander
The first few days bring a mild lisp and a preference for softer food; both pass quickly. Turning the screw is a two-second job most parents find easier than expected. Most children feel some pressure or soreness over the first few turns, and it usually eases as expansion continues (Barone et al., 2023). We see you regularly through the active phase, and those reviews can happen on a Saturday or Sunday so school is not interrupted.
Good to know
Common Questions
Can mewing widen my jaw instead?
There is no good clinical evidence that mewing reshapes the jaw. In adults the seam in the palate has usually fused, so tongue pressure alone is not expected to widen it. In children, healthy tongue posture and nasal breathing are part of normal development, and we assess both, but where the upper jaw is genuinely narrow an expander is the tool that has been studied.
Can adults have a palate expander?
Not a conventional one, in most cases, because the palate seam has usually fused. Adult options exist, including expanders anchored with small screws and surgically assisted expansion, and we refer to the right care where that is the best path.
Does expansion hurt?
Most children feel pressure or soreness over the first few turns, and it usually eases as expansion continues. Ordinary pain relief and soft food cover it.
Wondering About Your Child’s Palate?
A free orthodontic and airway consultation will tell you whether expansion is relevant to your child, or whether reassurance is all you need.
The free orthodontic and airway consultation includes a discussion of your concerns, a visual examination, general information about suitable options and an approximate plan and quote. It does not include diagnostic records, X-rays, photographs or a formal diagnosis; these are quoted separately if you choose to proceed, and your plan and quote may change if they show anything not visible at the examination. No obligation. One complimentary consultation per person. Orthodontic treatment is provided by general dentists with additional orthodontic training.
The research behind this page
- Harari D, et al. The effect of mouth breathing versus nasal breathing on dentofacial and craniofacial development. The Laryngoscope, 2010.
- Huang YS, Guilleminault C. Pediatric obstructive sleep apnea and the critical role of oral-facial growth. Frontiers in Neurology, 2013.
- Baratieri C, et al. Does rapid maxillary expansion have long-term effects on airway dimensions and breathing? American Journal of Orthodontics and Dentofacial Orthopedics, 2011.
- Camacho M, et al. Rapid maxillary expansion for pediatric obstructive sleep apnea: a systematic review and meta-analysis. The Laryngoscope, 2017.
- Yu M, et al. Orthodontic appliances for the treatment of pediatric obstructive sleep apnea: a systematic review and network meta-analysis. Sleep Medicine Reviews, 2023.
- Bucci R, et al. Effect of orthopedic and functional orthodontic treatment in children with obstructive sleep apnea: a systematic review and meta-analysis. Sleep Medicine Reviews, 2023.
- Yu K, et al. The effect of rapid maxillary expansion on children with obstructive sleep apnea: a systematic review and meta-analysis. Sleep and Breathing, 2026.
- Barone M, et al. Pain during rapid maxillary expansion: a systematic review. Children, 2023.
- Marcus CL, et al. Diagnosis and management of childhood obstructive sleep apnea syndrome. Pediatrics (AAP clinical practice guideline), 2012.
Inline Smiles Dental & Orthodontics: orthodontic treatment provided by our experienced general dentists. Where specialist care is in your best interest, we will tell you and refer you. This page is general information only, not a diagnosis or a personal treatment recommendation. Research findings describe groups, and individual results vary; suitability for any treatment is assessed individually.