🗣️ How Mouth Posture Affects Function — and Why It Matters More Than You Think

Helping feeding, speech, and function take flight for little ones in Santa Barbara.

What’s This About?

As a speech therapist specializing in orofacial myofunctional therapy (OMT), I often talk with families about things we don’t usually think about—like how your tongue and lips rest when you’re not talking, eating, or smiling.

A study published in Clinical Oral Investigations in 2011 looked at what’s going on inside the mouth when it’s “at rest” — and found something really interesting:

👉 Gentle air pressure changes inside the mouth (even without muscle activity) can help stabilize oral structures like the tongue and teeth.

This matters a lot—not just for orthodontic stability, but for speech, swallowing, breathing, and overall orofacial health.

What Did the Study Look At?

Researchers measured air pressure in two parts of the mouth:

• Between the teeth (when they aren’t touching)

• Under the palate (the space between the tongue and roof of the mouth)

They tested participants in four common postures:

1. Mouth open

2. Mouth gently closed

3. Mouth closed with suction (like right after swallowing)

4. During swallowing

   
   

What They Found

• When the lips are sealed and the tongue rests on the palate, the mouth naturally creates a gentle suction - almost like a mini vacuum.

• This negative intra-oral pressure helps keep the tongue and soft tissues in place without active muscle contraction.

• The strongest and most stable pressure happened after a complete swallow followed by a closed-lip posture.

• This pressure stayed even when the person was “doing nothing”—meaning the body naturally maintains oral stability when posture is correct.

Why This Matters in Myofunctional Therapy

A young patient with braces receives a myofunctional therapy session to enhance orthodontic outcomes and promote optimal oral posture.

Whether a child is in treatment for tongue thrust, open-mouth posture, articulation disorders, orthodontic relapse, or sleep-disordered breathing - this research backs up what we emphasize in therapy:

✅ Proper oral rest posture matters

✅ The tongue should rest on the roof of the mouth

✅ Lips should be together at rest

✅ Swallowing should be efficient and followed by a sealed oral cavity

These aren’t just “good habits”—they create a stable pressure system inside the mouth that supports natural development, clear speech, and healthy breathing patterns.

What You Can Do at Home

Here are a few ways to support healthy oral posture:

🛑 Avoid chronic mouth breathing—especially during sleep

👅 Encourage tongue-up rest posture (gently touching the palate)

👄 Remind kids to keep lips together during rest

💧 Hydrate well to support proper saliva flow and reduce dry mouth

🗓️ Follow through with OMT exercises if your child is in therapy

These small daily habits help reinforce the kind of stable, functional posture that leads to long-term health benefits.

Final Thoughts

We often think that only muscles move the tongue and shape the mouth—but this study reminds us that the pressures created by good posture are just as important. For SLPs and parents working together, it’s one more reason to build awareness of oral rest posture and support consistent therapy at home.

👉 Schedule a Consultation or Evaluation

Research Reference:Engelke W, Jung K, Knösel M. Intra-oral compartment pressures: a biofunctional model and experimental measurements under different conditions of posture. Clinical Oral Investigations. 2011;15(2):165–176. doi: 10.1007/s00784-009-0367-0