Resources/References

Pathogenesis of Orofacial Pain

Trigeminal Nerve Overview

Ophthalmic Branch (CN-V1)

The ophthalmic branch of the trigeminal nerve is otherwise known as the fifth cranial nerve, branch one (CN-V1).

The ophthalmic branch of the trigeminal nerve follows a path from in front of the ear, under the cheekbone, then directs upwards by the apple of the cheek to circle above the eye socket and back down toward the top of the nose.

The innervation of the ophthalmic branch of the trigeminal nerve:

  • forehead
  • eye
  • sinuses
  • anterior nose
  • scalp
  • parts of meninges

Maxillary Branch (CN-V2)

The maxillary branch of the trigeminal nerve is otherwise known as the fifth cranial nerve, branch two (CN-V2).

The maxillary branch of the trigeminal nerve follows a path from in front of the ear, under the cheekbone, and through the roof of the mouth before directing down toward the teeth in the upper jaw.

The innervation of the maxillary branch of the trigeminal nerve:

  • cheek
  • lower eyelid
  • upper lip
  • upper teeth
  • upper gums
  • hard palate

Mandibular Branch (CN-V3)

The mandibular branch of the trigeminal nerve is otherwise known as the fifth cranial nerve, branch three (CN-V3).

The mandibular branch of the trigeminal nerve follows a path from in front of the ear down the bottom of the jaw, before directing upward toward the teeth in the lower jaw.

The innervation of the mandibular branch of the trigeminal nerve:

  • lower lip
  • lower teeth
  • lower gums
  • chin
  • jaw (except mandibular angle)
  • tongue (via the lingual nerve branch)

Primary Afferent Nerves

Nociceptive Signal Transduction

Pathogenesis Descriptions

Organic Etiologies

Some diseases and syndromes may mask as Burning Mouth Syndrome, including:

  • Facial palsies or parotid tumors that can impinge on the facial nerve and cause dysesthesia, numbness, persistent pain, or dry mouth.
  • Cancer
  • Xerostomia (dry mouth due to lack of salivary flow)

Burning Mouth Syndrome

Bilateral pain on anterior 2/3 of the tongue. May be idiopathic or secondary due to mechanical or local factors. Proposed theories include:

  • Crosstalk dysfunction of sensory processing between trigeminal and facial nerves in patients considered to be “supertasters.”
  • Small and large fiber neuropathy, although pain is frequently bilateral along with oral autonomic dysfunction.
  • Centrally-mediated dopaminergic dysfunction leading to sensitization.

Glossopharyngeal Neuralgia

Pain on the posterior 1/3 of the tongue. Patho-etiologies may be idiopathic or secondary in nature. Secondary causes include:

  • Demyelinating lesions of Cranial Nerve IX and X
  • Peritonsillar abscess
  • Carotid aneurysm
  • Vascular compression
  • Metabolic abnormalities

Trigeminal Neuralgia

Most commonly described as unilateral short, sharp paroxysm. May be idiopathic or most frequently caused by direct vascular compression of Cranial Nerve V (trigeminal nerve). Other causes include:

  • Demyelinating disorder
  • Centrally-mediated pain generators
  • Sensitization leading to allodynia, or light touch pain triggers

Post-Herpetic Neuralgia

Following herpes zoster infection, inflammation may occur at the level of the peripheral nerve, the trigeminal root, or the trigeminal ganglion leading to nerve fibrosis.

Temporomandibular Neuralgia

Temporomandibular join disorder, or TMD, may arise from numerous proposed etiologies.

  • Direct joint trauma, inflammation, and degeneration
  • Variations in pain threshold (psychosomatic)
  • Posture and position of the head, neck, and jaw

Pathogenesis Review Questions

Which of the following descriptions corresponds to symptoms of Burning Mouth Syndrome?

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Which of the following descriptions corresponds to symptoms of Glossopharyngeal Neuralgia?

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Which of the following descriptions corresponds to symptoms of Trigeminal Neuralgia?

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Which of the following descriptions corresponds to symptoms of Post-Herpetic Neuralgia?

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Which of the following descriptions corresponds to symptoms of Temporomandibular Disorder?

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Review Articles

The following represent freely available review articles about Burning Mouth Syndrome:

  • Miziara 2015: Therapeutic Options in Idiopathic Burning Mouth Syndrome
  • Coculescu 2014: Burning Mouth Syndrome: a Review on Diagnosis and Treatment
  • Kohorst 2015: The Prevalence of Burning Mouth Syndrome
  • Aravindham 2014: Burning Mouth Syndrome: a Review on Its Diagnosis and Therapeutic Approach
  • Gurvits 2013: Burning Mouth Syndrome

Related Websites

NIDCR: National Institute of Dental and Craniofacial Research
Mayo Clinic
AAOM: The American Academy of Oral Medicine
ACPA: American Chronic Pain Association
ADA: American Dental Association
AAOP: American Academy of Orofacial Pain

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