Your child needs a palate expander because their upper jaw is too narrow. You understand the goal: create more room and improve how the teeth fit together.

But there is another question worth asking: Where has their tongue been resting—and what happens once there is more room?

The tongue, lips, and surrounding muscles are part of the environment in which your child’s teeth and dental arches develop. When expansion is needed, their function deserves attention, too.

Some children benefit from expansion alone. Others also need help with tongue posture, swallowing, lip closure, or other oral muscle patterns. A myofunctional evaluation helps determine what your child needs and how that fits into their orthodontic care.

New to myofunctional therapy? Here’s what it involves and who it can help.

Why tongue resting posture matters

Parents are rarely asked to think about where their child’s tongue rests when they are not eating or talking.

Yet the tongue, lips, and cheeks exert gentle pressures that influence tooth position. The American Academy of Pediatric Dentistry explains that these sustained resting pressures matter more than the brief contact that occurs during swallowing.[1]

That is why we need to look at what happens between swallows, throughout the day.

Does the tongue rest comfortably within the dental arch? Does it habitually press against or sit between the teeth? Can your child lift it toward the palate without excessive jaw movement? Can they keep their lips together comfortably?

A narrow upper jaw is a clue to investigate tongue posture. It does not identify the cause on its own, but it gives us a reason to ask these questions.

The relationship between space and function can work in both directions. Limited space can make appropriate tongue positioning difficult, while an unfavorable resting pattern may contribute to how the dental arch develops. We need to consider both when planning treatment.

More room does not automatically mean a new resting posture

A palate expander gradually widens the upper jaw. After active expansion, the appliance generally remains in place for a period of stabilization.[2]

That structural change can be important. But creating space does not tell us whether the tongue is now resting and functioning appropriately.

Can your child comfortably use that space? Has their swallowing pattern changed? Are they continuing the same muscle patterns they used before expansion?

These are things to reassess.

A 2025 study examined children with low tongue posture who received expansion with or without myofunctional therapy. Based on three-dimensional imaging, tongue posture improved in:

• 51.2% of the 43 children receiving expansion alone.
• 76.1% of the 46 children receiving expansion plus myofunctional therapy.[3]

That helps explain why the two treatments may be recommended together. Expansion addresses the structural concern, while therapy provides targeted work on the functional concerns identified during the evaluation.

We should check whether function has improved rather than assume it changed because the jaw is wider.

It may involve more than the tongue

The tongue works with the lips, cheeks, jaw, and surrounding muscles. Problems involving these muscles can occur together.[4]

In my evaluations, I look beyond where the tongue rests. I also look at how a child accomplishes everyday tasks.

For example, a child may push their tongue forward during swallowing, tighten their lips, or recruit the mentalis—the chin muscle that can create a puckered or dimpled appearance. I also watch for excessive jaw movement or visible head and neck effort.

Those observations help us ask: Are these muscles working together comfortably, or is the child using extra effort to accomplish the task?

Research has documented altered activity in several oral and facial muscles during lip closure and swallowing in young people with certain bite problems.[5]

Not every child has the same combination. That is why an evaluation should examine how the muscles work together, rather than focus on a single tongue exercise.

Why muscle function belongs in the orthodontic plan

The tongue, lips, and cheeks continue to exert pressure during orthodontic treatment and afterward.[1]

If your child uses an unfavorable resting or swallowing pattern, that deserves attention alongside the structural correction. Myofunctional therapy addresses the functional problems we identify, while your orthodontist’s retention plan remains part of maintaining the dental correction.

What are we working toward?

The goal is healthy oral function that works with your child’s developing structures: appropriate resting posture, a coordinated swallow, comfortable nasal breathing, and balanced use of the surrounding muscles.

These patterns can affect how your child’s face looks at rest, including whether their lips remain apart or their chin tightens to close their mouth.[4,5] We also ask about breathing and sleep because those concerns may need coordinated care. Our goal is comfortable, coordinated function that carries into everyday life.

We want these skills to become part of everyday life. Being able to demonstrate an exercise during an appointment is a step toward that goal, but we also want to see how your child rests, breathes, and swallows without repeated reminders.

Ideally, have the evaluation before expansion

My recommendation is to have a myofunctional evaluation before the expander goes in.

That gives us a baseline. We can document tongue and lip resting posture, swallowing, movement patterns, and breathing concerns before the structure changes.

Then, as orthodontic treatment progresses, we have something meaningful to compare:

• What improved with expansion?
• What still needs attention?
• Has your child developed the ability to use the additional space comfortably?

Depending on the findings, some therapy may be appropriate before expansion or while the appliance is in place. Other work may be better timed for after removal. We coordinate that with your orthodontist and account for the appliance, your child’s readiness, and any barriers to treatment.

For example, if nasal obstruction makes closed-mouth posture difficult, that needs appropriate attention rather than simply asking your child to keep their lips together.[4]

If your child already has an expander, you have not missed your opportunity. Contact us to discuss timing. If an evaluation did not occur prior to treatment, I recommend scheduling one soon after the appliance is removed to assess how your child is functioning with the new space.

Wondering what the appointment involves? Read what to expect at your child’s myofunctional evaluation.

Make function part of your child’s expansion plan

You may not know where your child’s tongue rests, but you may notice how they eat, breathe, or sleep. Bring these observations to their evaluation:

• Their mouth often hangs open, even when they are relaxed or concentrating.
• They regularly breathe through their mouth, including when they do not have a cold.
• They snore or grind their teeth during sleep, or you notice frequent jaw clenching.
• Frequent drooling during the day or regularly waking with a wet pillow.
• Eating seems like hard work—they chew for a long time, struggle with certain textures, or avoid foods that require more chewing.
• Their tongue comes between their teeth when resting, talking, or swallowing.
• Their lips squeeze or their chin puckers when they swallow or try to close their mouth.
• They have a persistent lisp or other speech-sound concerns.
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These observations can have different causes. They help guide the evaluation; they do not automatically mean your child needs myofunctional therapy.

You do not have to recognize a tongue or muscle problem yourself. That is what the evaluation is for.

At Functional Face, we assess whether orofacial myofunctional disorders are present and whether those findings may be contributing to your child’s concerns. We examine tongue and lip function, resting posture, and swallowing, alongside their breathing, sleep, and dental history.

Then we explain what we found, what needs attention, and how our recommendations fit with your child’s orthodontic care.

Schedule a myofunctional evaluation with Functional Face—ideally before expansion—to establish a baseline and determine whether therapy should be part of your child’s treatment plan.

Has your child also had tonsil and adenoid surgery? Read why mouth breathing can continue after surgery and what deserves a closer look.

This article provides general education and does not replace an individualized evaluation.

References

1. American Academy of Pediatric Dentistry. Management of the Developing Dentition and Occlusion in Pediatric Dentistry.
2. American Association of Orthodontists. What Is a Palatal Expander, and What Is It Used For?
3. Maeo K, et al. Low Tongue Posture Improvement Effect of Orofacial Myofunctional Therapy: Comprehensive Study of Nasal Ventilation Condition Using Computational Fluid Dynamics and Dental Arch Morphology. Orthodontics & Craniofacial Research. 2025;28(5):872–881. doi:10.1111/ocr.70000.
4. American Speech-Language-Hearing Association. Orofacial Myofunctional Disorders. Practice Portal.
5. Electromyographic Features and Efficacy of Orofacial Myofunctional Treatment for Skeletal Anterior Open Bite in Adolescents: An Exploratory Study. 2021.