Maxillary Hypoplasia in Children with Down syndrome

When we talk about orthodontics in children with Down syndrome, most people think about crooked teeth or braces. But there’s a much bigger story here. Many of our kids experience maxillary hypoplasia, or underdevelopment of the upper jaw. And that single issue doesn’t just affect their smile it has a ripple effect on the whole body.

Maxillary hypoplasia is not random. It’s actually a direct result of the trisomy. Research shows it can be identified as early as the second trimester in utero. So by the time a baby with Down syndrome is born, we’re already seeing structural differences in the midface that will go on to affect breathing, hearing, sleep, and learning. It has even been hypothesized that this is the reason for the distict eye shape of children with DS.

The midface internally is home to some of the most important systems in the body. When the maxilla is too small, it can impact the pituitary gland, which is tucked right behind it and plays a role in hormone regulation and growth. If the pituitary gland can not grow properly because it’s bony cradle is restrictive, it affects thyroid stimulating hormone, growth and pubertal hormines, and hormones that control night time continence, to name just a few.

Maxillary hypoplasia also affects the airway which sets the stage for sleep-disordered breathing and even obstructive sleep apnea. These issues we know are far too common in our children with DS.

If the bone is too small, the drainage openings are as well. This means the sinuses can’t drain well, which leaves our children dealing with congestion and chronic infections. A too-small maxilla means poor drainage through the Eustachian tubes, which leads to ear infections, fluid buildup, and often, hearing loss.

The effect on speech can not be over stated. With low muscle tone and a too-small maxilla, it appears as if the tongue is too large for the mouth making articulation and sound myofunctional skills impossible. This affects skills like speech, swallowing, chewing, sleep, and open-mouth posture.

I need to caution about one other thing. Teeth crowd because the maxilla is too smal. The teeth are not the problem, they are a symptom. If the approach is to pull teeth and close the space with braces, you are effectively making the maxilla smaller. The teeth might look nice,, but all the underlying structures are being profoundly impacted.

So, when we’re looking at maxillary hypoplasia, we’re not just talking about orthodontics. We’re talking about sleep, learning, behavior, communication, and overall health.

Expansion Approaches

There are a few ways orthodontists might approach the issue of Maxillary Hypoplasia. First, it is critical to find a practitioner that understands the unique feature of trisomy 21. Often, you might find an orthodotist willing to expand, but they do not understand the specific morphology and therefore will advise against repeated expansions, which are necessary in a genetic condition that will cause the issue to repeat until the child is done growing.

Rapid Maxillary Expansion (RME)/ Or Rapid Palate Expansion (RPE) uses a device to widen the upper jaw quickly by putting force on the palate. With RME you achieve 1/2″ space in 30 days. The research suggest the rapid nature of the maxilla stimulates further growth.

Many parents have found success with Airway Orthodontists . These practitioners are uniquely knowledgable about the physiological reasons necessary to repeatedly expand in our children. In some studies RPE increasd airway efficiency by 400%! Because our kids often have different bone density, tolerance levels, and nervous system sensitivities, it can be stressful if we don’t pair it with strong regulation supports.

Slow expansion takes a gentler approach by using lighter forces, spread out over more time. It’s often easier for children to adapt to and gives us time to watch how their airway, sinuses, and ears respond. It takes more patience, but it can lead to very stable results.

And then there’s a piece that often gets missed: anterior expansion. It’s not enough to widen the upper jaw. We need to “pull it forward” too, to make room for proper tongue posture, to support a lip seal, and to help balance overall facial growth. This is especially important if the child uses a forced air mask for sleep. They repress the maxilla further. Often times “hooks” for the headgear are embedded into the expander so the parent simply hooks the headgear on with rubber bands. I say simply, but – you know – not so simple.

Expansion appliances aren’t the only part of the picture. Myofunctional therapy is targeted exercises that strengthen the tongue, lips, and orofacial muscles. In addition to therapy, tools like the Myomunchee or specialized straws for oral motor strengthening can support development and help retrain oral posture.

One of the biggest goals here is to strengthen the posterior of the tongue. When the back of the tongue is weak, it tends to collapse backward during sleep, partially blocking the airway. By targeting posterior tongue strength, we not only support speech and feeding, but also reduce the risk of airway obstruction at night.

Foundations of Readiness

No matter which method is used, expansion can feel overwhelming for a child. It’s about physiological safety. It’s about their nervous system.

It does start with the parent’s mindset. Children co-regulate with us. If we approach orthodontic care with fear, stress, or uncertainty, our children will pick up on that energy instantly. Preparing ourselves, learning about the process, regulating our own nervous system, and creating a calm, confident presence, is the very first step. When parents feel grounded, children feel safer.

From there, we can build readiness with the child. We will be talking in depth about these issues as DSAP moves along with the creation of its building tolerance program. The main concepts are:

• Regulation first: calming routines like breathing, rhythmic movement, or vagus work before appointments. There are many regulation and co-regulation activities in the dsactioplan.com/blog.

• Visualization – If the child is old enough, this can be a guided visualization where the parent calmly walks them through what it will look like, taste like, sound like, and feel like. For younger children, keep it simple by using a drawing or picture as a reference point for focus.

• Social stories – personalized narratives that make the process predictable and supportive.

• Rehearsal – practicing with safe, non-threatening tools so “something in my mouth” isn’t brand new. Even better if the orthodontist gives you exact items that will be used during the procedure to allow the child to explore on their own terms.

• Co-regulation during the session – a trusted adult present to model calm breathing and offer reassurance.

• Oral motor desensitization work – introducing gentle oral motor activities ahead of time to reduce sensitivity and help the child adapt more smoothly to new sensations.

When parents are steady, and children feel safe, they can tolerate what otherwise feels impossible. And when they can tolerate expansion, we’re not just widening a jaw, we’re opening airways, supporting growth, protecting hearing, and building a foundation for learning and thriving.

Some Questions to Ask a Prospective Orthodontist

The goal of the questions are to find out how experienced the practitioner is with maxillary hypoplasia and to understand their approach.

1. Do you work with many children who have Maxillary Hypoplasia from DS?
2. What is your recommended rate of expansion? Fast / Slow, why?
3. Will Myofunctional Therapy be part of the plan?
4. Will you / your team comply with my child’s regulation / desensitization program?
5. What is the plan to measure airway development?
6. What are the intervals you would recommend expanding to maintain appropriate head ratios throughout the growth period?
7. Will the appliance be left in the mouth for a longer period of time after expansion is complete?
8. What else will be added to a holistic plan for health, development, and breathing?

Research

Honestly, it is my opinion if an orthodontist questions you about where you got the information, or otherwise tries to suppress your inquiry, they are not the right choice. However, for your reference, I have put together a list of research. Often in the past, parents would arm themselves with research to avoid being dismissed. Again, if you feel you need to do that, I would find another practitioner.

Notes for families:

• Direct Down syndrome-specific studies show RME can increase nasal volume, and in RCTs reduce ENT infections and improve hearing vs. no treatment.
• In DS, a published case report documents marked OSA improvement after RME.
• In the general pediatric literature, systematic reviews and clinical studies show RME tends to increase upper-airway volume and can lower AHI in select patients (evidence quality and long-term durability vary).
• Early hormone-axis signal: a randomized thesis found IGF-1 increased and AHI decreased after maxillary expansion (non-syndromic). Evidence linking RME directly to puberty or thyroid outcomes in children—especially in DS—remains limited.

Bicakci, A. A., Agar, U., Sökücü, O., Babacan, H., & Doruk, C. (2005). Nasal airway changes due to rapid maxillary expansion timing. Angle Orthodontist, 75(1), 1–6. 

Camacho, M., Chang, E. T., Song, S. A., et al. (2017). Rapid maxillary expansion for pediatric obstructive sleep apnea: A systematic review and meta-analysis. Laryngoscope, 127(7), 1712–1719. 

de Julián-López, C., Martínez-González, A., Candelas-Martín, J., et al. (2023). Upper airway changes after rapid maxillary expansion: Three-dimensional analyses. BMC Oral Health, 23, 544. 

de Moura, C. P., Vales, F., Andrade, D., Cunha, L. M., Barros, H., Pueschel, S. M., & Pais Clemente, M. (2005). Rapid maxillary expansion and nasal patency in children with Down syndrome. Rhinology, 43(2), 138–142. 

Galeotti, A., Ierardo, G., Luzzi, V., et al. (2023). Effects of rapid palatal expansion on the upper airway space in children with obstructive sleep apnea: A case-control study. Children, 10(2), 244. 

Gianoni-Capenakas, S., et al. (2020). Review: Rapid maxillary expansion and airway—what do we really know? Journal of Dental Sleep Medicine, 7(4), e2020. (Review). 

Inchingolo, A. D., et al. (2022). Rapid maxillary expansion on the adolescent patient. Children, 9(7), 1046. 

Kim, A., Cho, H. J., Choi, E. K., & Choi, Y. J. (2022). Improvement in obstructive sleep apnea in a child with Down syndrome with rapid palatal expansion. Journal of Clinical Sleep Medicine, 18(7), 1885–1888. 

Kinzinger, G. S. M., et al. (2023). Age-dependent effects on palate volume and morphology after rapid maxillary expansion. Scientific Reports, 13, 8401. 

McNamara, J. A., Jr., Sigler, L. M., & Franchi, L. (2015). The role of rapid maxillary expansion in the promotion of oral and general health. Progress in Orthodontics, 16, 3. (Review). 

Outumuro, M., Abeleira, M. T., Otero, X. L., et al. (2010). Maxillary expansion therapy in children with Down syndrome. Pediatric Dentistry, 32(7), 499–504. 

Pinto de Moura, C., Andrade, D., Cunha, L. M., et al. (2008). Down syndrome: Otolaryngological effects of rapid maxillary expansion. The Journal of Laryngology & Otology, 122(12), 1318–1324. (Randomized clinical trial). 

Santana, D. M. C., et al. (2021). The effect of rapid maxillary expansion in children: A meta-analysis. Brazilian Journal of Otorhinolaryngology, 88(5), 739–748.  

Shetty, N., Khandelwal, A., Bhadrashetty, D., et al. (2022). Effect of maxillary expansion protocols on maxillary sinus volume, pharyngeal airway volume, and hyoid position. Open Dentistry Journal, 16, e187421062208220. 

Simpson, R., Oyekan, A. A., Ehsan, Z., & Ingram, D. G. (2018). Obstructive sleep apnea in patients with Down syndrome: Current perspectives. Nature and Science of Sleep, 10, 287–293. (DS review; includes RME context). 

Vu, D. (2021). Effects of rapid maxillary expansion on serum IGF-1 and apnea–hypopnea index in prepubertal children with maxillary constriction (Master’s thesis). University of Alberta. 

Yoon, A., Kho, S. J., Cha, J., et al. (2022). Impact of rapid palatal expansion on the size of adenoids and tonsils in children. Sleep Medicine, 95, 31–39.