When we think about speech clarity, we usually focus on the tongue and lips. But there’s one critical piece that often gets overlooked: the jaw. Without stable jaw support, all the fine, precise movements required for speech can break down—and intelligibility can suffer in a major way.

Whether you're working with young children developing speech or adults recovering from neurological injuries, jaw stability plays a foundational role in clear communication. Let’s break it down:

How Jaw Instability Affects Speech Intelligibility
Jaw instability doesn’t just create a little wobble—it disrupts the entire speech production system. Here's what happens when the jaw lacks control:

Poor Base of Support: The jaw acts like the anchor for the tongue and lips. Without a steady base, these smaller, faster-moving articulators struggle to move accurately and efficiently.

Shaky or Excessive Movements: Instead of smooth, intentional movements, you may see exaggerated or poorly timed jaw motion that throws off articulation.

Imprecise Sound Production: Sounds that require precise tongue and lip placement—like /s/, /z/, /sh/, /ch/, /j/, /t/, /d/, /l/, and even vowels—can become distorted, slurred, or mumbled.

Reduced Listener Understanding: Ultimately, unstable jaw movement makes speech harder to understand, leading to frustration for both the speaker and their communication partners.

In short: if the jaw isn’t stable, the entire system is shaky—and intelligibility drops.

How to Increase Jaw Stability in Therapy
The good news? Jaw stability can be improved with targeted intervention focused on strength, control, and awareness. Here are some proven techniques:

1. Jaw Grading Exercises
Help clients practice controlled opening and closing at different levels: small, medium, and large mouth openings—all while maintaining symmetry.
✅ Use mirrors for visual feedback.
✅ Add tactile cues (like a hand lightly touching the chin) to guide awareness.

2. Bite Block Training
Introduce bite blocks (or even small objects like Popsicle sticks) between the molars to create a stable jaw position during exercises.
✅ Practice tongue movements and simple speech sounds while maintaining the bite block.
✅ Start with larger blocks and gradually reduce size as control improves.

3. Chewing Exercises
Strengthen the muscles of mastication with controlled chewing tasks:
✅ Encourage chewing evenly on both sides of the mouth.
✅ Use tough or resistive foods (gum, dried fruit, bagels) to increase endurance safely.

4. Jaw Resistance Training
Build strength and stability with gentle resistance activities:
✅ Apply light pressure against jaw opening or closing (using a hand or therapy tool).
✅ Focus on slow, steady movements without tension.

5. Speech Drills with Stabilization
Combine jaw control with real speech tasks:
✅ Practice multisyllabic words, rapid speech drills, or reading aloud while focusing on jaw steadiness.
✅ Add external cues if needed to maintain stability during faster speech rates.

6. Awareness Techniques
Help clients learn to notice when their jaw is moving unnecessarily:
✅ Teach them to “feel” the difference between stable and unstable jaw movement.
✅ Use video feedback, mirrors, or tactile input to increase body awareness.

Important Reminder:
The goal isn’t to create a stiff, locked jaw. We’re aiming for controlled mobility—a balance between stability and flexibility, like a dancer's graceful control. The jaw needs to be strong enough to provide a foundation but flexible enough to allow natural, fluent movement during speech.

When you build jaw stability first, everything else—tongue movements, lip precision, articulation accuracy—becomes easier and more efficient. It’s one of the best investments you can make for improving overall speech intelligibility.

​At Simon Says Speech, we believe in addressing the whole system—jaw, tongue, breathing, habits, and more. Our programs and tools are designed to give you the step-by-step support you need to build lasting change for your clients. Ready to level up your impact? Explore our myofunctional therapy resources today!