Neurophysiology in Orofacial Intervention: Mechanisms, Modulation, and Clinical Implications

By Dr. Evan Friedman | February 18, 2026 |

Introduction: Why Neurophysiology in Orofacial Intervention Matters

Neurophysiology in orofacial intervention is foundational to understanding persistent pain, functional adaptation, and therapeutic response. Although many dental and orofacial treatments focus on structural or mechanical factors, the trigeminal system functions as a dynamic and plastic neural network.

Orofacial pain neurophysiology involves:

Peripheral and central sensitization
Neuron–glia interactions
Cortical neuroplasticity
Descending pain modulation
Affective–sensory integration

Understanding these mechanisms helps clinicians better match interventions to the underlying pathophysiology.

Peripheral and Central Sensitization in Orofacial Pain

Persistent orofacial pain frequently reflects both peripheral and central sensitization.

Following trigeminal nerve injury or inflammation, neuroplastic changes occur within:

The trigeminal ganglion (TG)
The trigeminal spinal subnucleus caudalis (Vc)
Upper cervical spinal cord segments (C1/C2)

These adaptations increase neuronal excitability and produce ectopic hypersensitivity [1].

Crucially, sensitization involves both neurons and glial cells. Satellite glial cells, macrophages, microglia, and astrocytes contribute to heightened excitability through functional neuron–glia interactions [1].

This explains why chronic trigeminal neuropathic pain cannot be managed by peripheral treatment alone. Central mechanisms must also be addressed.

Cortical Neuroplasticity and Sensorimotor Integration

Neuroplasticity in dentistry is most evident in the primary somatosensory cortex (SI) and primary motor cortex (MI) of the face. These regions demonstrate adaptive capacity in response to altered oral states and motor behaviours [2].

The face sensorimotor cortex supports:

Chewing and swallowing
Voluntary facial movement
Sensorimotor integration
Adaptation to prosthetic rehabilitation

Cortical plasticity explains how patients adapt to:

Dental prostheses
Implant-supported restorations
Occlusal modifications

Importantly, neuroplastic capacity persists in older adults. Functional adaptation depends more on cognitive and motor learning capacity than on chronological age [2].

Descending Pain Modulation in the Trigeminal System

Descending pain modulation plays a critical role in the mechanisms of chronic orofacial pain.

Serotonergic circuits from the rostral ventromedial medulla facilitate the activation of second-order neurons in the trigeminal nucleus complex. These pathways contribute to mechanical hyperalgesia in conditions such as masseter muscle inflammation [3].

Dysregulated endogenous pain modulation contributes to chronic muscle pain disorders [3].

For clinicians, this underscores the importance of multimodal approaches that target both peripheral triggers and central amplification.

Neural Pathway Organization and Affective Integration

Craniofacial muscle afferents project widely throughout the trigeminal nucleus complex. Second-order neurons transmit signals to:

Sensory-discriminative pathways (ventral posteromedial thalamic nuclei)

Affective-motivational pathways (parabrachial nucleus, medial thalamic nucleus) [3]

The anterior insula integrates pain perception, interoception, and salience processing. A neuroimaging meta-analysis confirms its role in the association between mastication and orofacial pain [4].

Orofacial intervention must therefore consider both sensory intensity and affective processing.

Neuromodulation for Orofacial Pain

Neuromodulation techniques have emerged as promising therapies for chronic orofacial pain.

Repetitive transcranial magnetic stimulation (rTMS) targeting the motor cortex (M1), the dorsolateral prefrontal cortex (DLPFC), and the secondary somatosensory cortex (S2), as well as transcranial direct current stimulation (tDCS) targeting M1, have demonstrated efficacy [5].

These approaches likely work by modulating cortical excitability and reorganizing pain-processing networks [5].

Neuromodulation represents a practical application of neuroplastic principles in dentistry.

Which Patients Benefit Most from Orofacial Intervention?

Trigeminal Neuropathic Pain

Patients with posttraumatic trigeminal neuropathic pain (PTTNP), burning mouth syndrome (BMS), and persistent idiopathic facial pain (PIFP) often show neurophysiological abnormalities despite normal clinical examination [6].

Myogenous TMD with Myofunctional Disorders

Adults with myogenous temporomandibular disorders (TMD) and/or orofacial myofunctional disorders show improvements in maximum mouth opening; tongue mobility; mechanical pain thresholds; and pain intensity after targeted therapy [7,8].

Prosthetic Rehabilitation and Adaptation

Neuroplasticity enables adaptation to altered oral states, including prosthetic and implant-supported rehabilitation [2]. Elderly patients retain significant plastic potential when rehabilitation includes sensorimotor training paradigms [2].

Age, Comorbidity, and Orofacial Treatment Outcomes

Age alone does not determine treatment success in myofascial TMD [9].

However, comorbidities and polypharmacy influence:

Xerostomia
Healing response
Infection risk
Drug interactions
Medication-related osteonecrosis risk

Polypharmacy-associated xerostomia is highly prevalent among older adults and contributes to secondary complications [10,11].

Treatment planning should prioritize: Functional status; Medication reconciliation; Systemic disease burden; Cognitive capacity, rather than chronological age [12–14].

Clinical Integration: Applying Neurophysiology in Orofacial Intervention

Effective orofacial intervention requires integration of:

Peripheral and central sensitization assessment
Understanding of trigeminal system plasticity
Consideration of descending pain modulation
Recognition of affective pain pathways
Individualized risk assessment in multimorbidity

Neurophysiology in orofacial intervention is not theoretical. It is clinically actionable, whereas Dentistry is not solely structural. It is fundamentally neurophysiological.

References

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Chung MK, Wang S, Yang J, et al. Neural pathways of craniofacial muscle pain: implications for novel treatments. J Dent Res. 2020.
Chen TC, Lin CS. Neuroimaging meta-analysis of brain mechanisms of the association between orofacial pain and mastication. J Oral Rehabil. 2023.
Ferreira NR, Junqueira YN, Corrêa NB, et al. The efficacy of transcranial direct current stimulation and transcranial magnetic stimulation for chronic orofacial pain: a systematic review. PLoS One. 2019.
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