The Science Behind: Why Some Autistic Individuals Seek Lip & Tooth Pressure

What Sensory Neuroscience Can — and Cannot — Tell Us

A Research-Informed Educational Poster

Biting, pressing objects against the lips, applying pressure around the mouth or firmly clenching the teeth can provide tactile, oral-proprioceptive and trigeminal sensory input.

For some autistic people, this kind of self-generated oral input may feel predictable, organizing, grounding or helpful during concentration, uncertainty or periods of increased sensory load.

But the same visible action can have very different explanations.

The behaviour tells us what the person is doing — it does not automatically tell us why.

The Science Behind: Why Some Autistic Individuals Seek Lip & Tooth Pressure is a research-informed educational poster from Nonspeaking Autism exploring the sensory pathways involved in oral pressure while carefully distinguishing established sensory neuroscience from individual interpretation.

The central question is not simply:

“How do I stop it?”

but:

“What might this input be doing for their body and nervous system?”

👄 What Is Lip & Tooth Pressure?

Examples can include:

• biting or pressing objects against the lips
• pressing the lips firmly together
• biting down
• clenching the teeth or jaw
• applying pressure around the mouth
• repeatedly seeking firm oral input

These actions can generate sensory information from several structures and systems at the same time.

The experience may involve touch and pressure around the lips and mouth, information from the jaw and surrounding tissues, and sensory pathways involving the trigeminal system.

This makes oral sensory behaviour more complex than simply describing someone as liking to chew or bite.

1️⃣ Pressure at the Lips & Teeth

Firm pressure around the lips, teeth and oral area provides tactile sensory information.

When the person creates the pressure themselves, the input may also be relatively predictable and controllable.

For some individuals this may be an enjoyable sensory experience.

For others it may occur during concentration, waiting, excitement, fatigue or overwhelm.

And in other circumstances, biting or clenching may be associated with pain or physical discomfort.

One movement does not have one universal meaning.

2️⃣ Tactile & Oral-Proprioceptive Input

Touch receptors in and around the mouth provide information about contact and pressure.

Information associated with muscles, joints and movement also contributes to awareness of what the jaw and mouth are doing.

Together, these systems help the nervous system process information about:

touch • pressure • movement • force • body position

This helps explain the type of sensory information oral-pressure behaviours can generate.

It does not establish their function for a particular person.

3️⃣ Oral Sensory & Trigeminal Pathways

The trigeminal nerve is a major sensory pathway for the face and oral structures.

Sensory information from areas including the lips, teeth, gums, jaw and face travels through trigeminal pathways towards sensory nuclei in the brainstem and onward through wider sensory-processing networks.

These pathways contribute to experiences such as touch, pressure and pain.

The nervous-system illustration in this resource is deliberately simplified for education.

It should not be interpreted as a literal scan or individualized neurological explanation of oral sensory seeking.

4️⃣ Brain Filtering, Relay & Context

Sensory information is processed through interconnected neural systems.

The thalamus plays an important role in relaying much sensory information towards cortical regions, while attention, expectation, context and previous experience can influence perception.

This means the same physical input may not feel the same in every situation.

Sensory experience can be affected by:

• predictability
• personal control
• attention
• stress or arousal
• competing sensory information
• fatigue
• pain
• environment
• previous experiences

The sensory stimulus is only one part of the experience.

5️⃣ Body Map & Awareness

The somatosensory cortex contributes to representing and processing sensory information from different parts of the body.

It helps process features of touch, including information relevant to where stimulation occurs.

But touch and oral sensory experience are not produced by one brain area alone.

Multiple neural systems contribute to perception, attention, emotional significance, movement and response.

The brain diagram should therefore be understood as a simplified educational model rather than a complete map of an individual's sensory experience.

6️⃣ Regulation — What Can We Say?

For some individuals, repeated oral pressure may appear to accompany:

• concentration
• waiting
• excitement
• uncertainty
• sensory overload
• recovery
• periods of increased arousal

A person may experience self-generated oral input as calming, organizing, grounding, focusing or simply pleasant.

But this response is individual.

Current evidence does not establish that lip or tooth pressure has one universal regulatory effect for autistic people.

What helps one nervous system may not help another.

⚙️ What Might This Input Provide?

Depending on the individual and context, oral pressure may provide:

• strong sensory feedback
• predictable sensation
• self-generated tactile input
• oral-proprioceptive feedback
• an activity used during concentration
• an activity used during overwhelm or uncertainty
• a familiar sensory experience

These should be considered possibilities rather than predetermined functions.

🔍 Look at the Pattern

Rather than interpreting a single incident, observe what happens across different situations.

Consider:

Does it happen during overwhelm or uncertainty?

Does it increase while waiting or concentrating?

Is it more common when the person is tired, overstimulated or excited?

Does it increase in noisy or busy environments?

Does it happen during particular tasks or transitions?

Does the person actively seek the pressure?

Does it appear to help them continue or recover?

And, wherever possible:

Ask the person what the experience means to them.

Communication may be through speech, AAC, gesture, pointing, symbols, writing, behaviour or another individualized method.

🦷 Pain & Physical Health Must Be Considered

One of the most important messages in this resource is that oral pressure should not automatically be interpreted as sensory seeking.

New, sudden, intense or persistent biting, pressing or clenching can sometimes accompany discomfort.

Consider possible issues involving:

• teeth
• gums
• mouth sores
• jaw or temporomandibular area
• ear discomfort
• headache
• reflux or gastrointestinal discomfort
• injury
• other pain or illness

A behaviour change does not prove pain — but it can be a reason to check rather than assume.

Sensory explanations should never prevent appropriate dental or medical assessment.

🚫 Should We Automatically Stop It?

Not necessarily.

If an oral sensory behaviour is safe, comfortable and not causing injury, the fact that it looks unusual is not by itself a reason to eliminate it.

Instead ask:

Is it safe?

Is it damaging the teeth, lips or oral tissues?

Could the person be in pain?

Is the person choosing the input?

Is it helping or interfering with participation?

Has the behaviour suddenly changed?

Does the person need a safer way of obtaining similar input?

The goal should be understanding, safety and access — not making somebody appear less autistic.

🧠 An Important Distinction About Deep Pressure

Research into deep-pressure interventions provides useful context but should be interpreted carefully.

Some autistic individuals have shown beneficial responses to deep-pressure input, while responses vary significantly between people.

This does not mean research on externally applied deep pressure proves that biting, clenching or lip pressure produces the same physiological effect.

Oral self-generated pressure and externally applied deep-pressure interventions are different experiences.

Evidence from one should not automatically be transferred to the other.

🔬 Research-Informed

The scientific literature supports the broader principles behind this resource:

Sensory-processing differences are common in autism, although individual sensory profiles vary substantially.

Research has documented differences in tactile processing in autistic populations.

The trigeminal sensory system carries important sensory information from the face and oral structures.

Proprioceptive and tactile information contribute to body awareness and movement.

Responses to pressure-based sensory input can also differ considerably between individuals.

What the evidence does not establish is that a particular oral behaviour has one specific neurological purpose simply because the person is autistic.

Observe the pattern. Consider context. Check the body. Individualize support.

📚 Selected Research & References

Ben-Sasson, A., Gal, E., Fluss, R., Katz-Zetler, N., & Cermak, S. A. (2019). Update of a Meta-analysis of Sensory Symptoms in ASD: A New Decade of Research. Journal of Autism and Developmental Disorders, 49(12), 4974–4996.

Schaaf, R. C., & Lane, A. E. (2015). Toward a Best-Practice Protocol for Assessment of Sensory Features in ASD. Journal of Autism and Developmental Disorders, 45(5), 1380–1395.

Mikkelsen, M., Wodka, E. L., Mostofsky, S. H., & Puts, N. A. J. (2018). Autism spectrum disorder in the scope of tactile processing. Developmental Cognitive Neuroscience, 29, 140–150.

Riquelme, I., Hatem, S. M., & Montoya, P. (2016). Abnormal Pressure Pain, Touch Sensitivity, Proprioception, and Manual Dexterity in Children with Autism Spectrum Disorders. Neural Plasticity, 2016, 1723401.

van der Cruyssen, F., & Politis, C. (2018). Neurophysiological aspects of the trigeminal sensory system: an update. Reviews in the Neurosciences, 29(2), 115–123.

Bestbier, L., & Williams, T. I. (2017). The Immediate Effects of Deep Pressure on Young People with Autism and Severe Intellectual Difficulties: Demonstrating Individual Differences. Occupational Therapy International, 2017, 7534972.

1. Chen, Y., Xi, Z., Saunders, R., Simmons, D., Totsika, V., & Mandy, W. (2024). A systematic review and meta-analysis of the relationship between sensory processing differences and internalising/externalising problems in autism. Clinical Psychology Review, 114, 102516. doi:10.1016/j.cpr.2024.102516
2. Kim, H. K., Chung, K., Xing, J., Kim, H. Y., & Youn, D. (2024). The trigeminal sensory system and orofacial pain. International Journal of Molecular Sciences, 25(20), 11306. doi:10.3390/ijms252011306
3. López-Martínez, I., Galera-Martínez, R., Aparicio-Mota, A., López-Martín, J. M., Beaudry-Bellefeuille, I., & Parrón-Carreño, T. (2025). The impact of sensory reactivity and oral praxis on feeding participation in children with autism (SemAlTea Study). Behavioral Sciences, 15(11), 1577. doi:10.3390/bs15111577
4. Chauhan, A., Leadbitter, K., Gray-Burrows, K. A., Vinall-Collier, K., Pickles, N., Baker, S. R., Marshman, Z., & Day, P. F. (2025). An 'explosion in the mouth': The oral health experiences of autistic children. Autism, 29(3), 627–641. doi:10.1177/13623613241288628
5. Floríndez, L. I., Como, D. H., Law, E., Tran, C. F., Johnson, R., Polido, J. C., Cermak, S. A., & Stein Duker, L. I. (2025). Oral care interventions for autistic individuals: A systematic review. Autism, 29(1), 41–52. doi:10.1177/13623613241260171
6. Morris, I. F., Sykes, J. R., Paulus, E. R., Dameh, A., Razzaque, A., Vander Esch, L., Gruenig, J., & Zelazo, P. D. (2025). Beyond self-regulation: Autistic experiences and perceptions of stimming. Neurodiversity. doi:10.1177/27546330241311096

Sources:

• Chen et al. 2024 (University of Glasgow record)
• Kim et al. 2024 (MDPI)
• López-Martínez et al. 2025 (MDPI)
• Chauhan et al. 2025 (NIHR ARC Yorkshire & Humber)
• Floríndez et al. 2025 (SAGE)
• Morris et al. 2025 (CiteDrive record)

🔎 Evidence Note

These references support the broader sensory, tactile, proprioceptive and trigeminal principles discussed in the resource.

They should not be interpreted as proving that lip pressing, tooth pressure, biting or jaw clenching has a specific regulatory function in an individual autistic person.

The illustrated brain and sensory pathways are simplified educational representations rather than diagnostic or individualized neurological models.

👨‍👩‍👧 Who Is This Resource For?

This poster may be useful for:

• autistic people and their families
• parents and carers
• teachers and teaching assistants
• SENCOs and SEND teams
• occupational therapists
• speech and language therapists
• dentists and oral-health professionals
• paediatric and healthcare professionals
• support workers
• mainstream and specialist schools
• social-care teams
• autism and disability organisations

It can support parent education, staff training, professional discussion and individualized sensory-support planning.

📦 What You Receive

Your purchase includes:

1 × The Science Behind: Why Some Autistic Individuals Seek Lip & Tooth Pressure educational poster

1 × high-resolution printable digital PDF

The purchased file is supplied clear and without the promotional preview watermark shown on the Payhip listing image.

Watermarks visible in the Payhip listing images are used for preview and copyright protection only.

Digital download only — no physical product will be shipped.

⚠️ Important Disclaimer

This is a research-informed educational resource.

It is not medical advice, dental advice, diagnosis, occupational therapy assessment, sensory assessment, neurological assessment, pain assessment, behaviour assessment or an individualized treatment plan.

Examples in the resource describe possibilities and should not be used to assign a specific meaning to an individual's behaviour.

New, sudden, painful, intense, persistent or unexplained oral behaviours should not automatically be attributed to autism or sensory seeking.

Where there is tooth damage, oral injury, bleeding, swelling, significant pain, difficulty eating or drinking, facial swelling, persistent jaw symptoms or another concerning physical change, seek appropriate dental or medical assessment.

Sensory support should be individualized, safe and respectful of the person's preferences and autonomy.

©️ Copyright & Permitted Use

Copyright © 2026 Nonspeaking Autism. All rights reserved.

Purchase permits use for personal/home use, your own classroom or educational setting, your own clinic or individual professional educational practice, and direct educational/support work with people you support.

The file may not be resold, redistributed, file-shared, uploaded elsewhere, commercially reproduced, altered for resale or incorporated into another product for sale or distribution.

Please direct others who would like their own copy to the original Nonspeaking Autism listing.

💛 The Message Behind the Resource

When someone repeatedly bites, presses, clenches or seeks pressure around their mouth, the movement may be easy to see.

Its meaning is much harder to see.

It could be sensory.

It could support concentration.

It could occur during overwhelm.

It could simply feel good.

Or it could signal discomfort that deserves investigation.

That is why the first response should be curiosity rather than correction.

**Look at the pattern.

Check the context.

Check for pain.

Listen to the person.

Support safely.**

DON'T JUST ASK: “HOW DO I STOP IT?”

ASK: “WHAT MIGHT THIS INPUT BE DOING FOR THEIR BODY AND NERVOUS SYSTEM?”

Connection over correction. Understanding over expectation. 💙🌻

© Nonspeaking Autism 2026