Orofacial Pain

Question 1

Trigeminal Sensory Nuclei:

1. Chief Sensory Nucleus-
2. Mesencephalic Nucleus-
3. Spinal Nucleus-

Answer 1

Trigeminal Sensory Nuclei:

1. Chief Sensory Nucleus- discriminative touch andd conscious proprioception
2. Mesencephalic Nucleus- proprioception
3. Spinal Nucleus- pain, temperature, dull touch

Question 2

Why do we experrience a referral of pain in the orofacial region and have difficulty precisely locating pain?

Answer 2

Afferents (sensory neurons) from different regions of the orofacial region may converge on a single secondary afferent in the spinal trigeminal nucleus.

**some cervical afferents may also converge on this nucleus

Question 3

How do we localize pain and temperature?

Answer 3

Localization of pain and temperature is through the trigeminal pain and temperature fibers. They descend caudally to enter the spinal nucleus of V. From here, the fibers decussate and join the ascending spinothalamic tract as the trigeminothalamic pathway

Question 4

What is the indirect trigeminothalamic Pathway?

Answer 4

the indirect trigeminothalamic Pathway is analogous to the paleospinothalamic pathway in that it is multisynaptic.

It controls the motivational-affective aspects of pain; dull, aching prolonged pain.

Fibers from the spinal nucleus of V ascend bilaterally to the medial thalamic nuclei which in turn projects to the prefrontal and cingulate gyri

Question 5

Tooth Innervation:

1. dental pulp-
2. Dentin-

Answer 5

Tooth Innervation:

1. dental pulp- C fibers
2. Dentin- A(some fucking greek character that i can’t find) and free nerve endings are Aß fibers

Question 6

Pulpitis

1. etology
2. characteristics

Answer 6

Pulpitis

1. etology- infetion of the pulp or trauma to the tooth
2. characteristics- pain is dull, aching, and throbbing due to the innervation by C fibers

Question 7

Tooth Hypersinsitivity

1. etiology-
2. characteristics

Answer 7

Tooth Hypersinsitivity

1. etiology- due to lesion in the enamel exposing the dentin or exposure of root dentin
2. characteristics- pain is sharp, bright, stabing, excruciating

**innervation by the A(some greek character) is the trigeminothalamic pathway and free nerve endings from Aß fibers using the trigeminoleminiscal pathway

Question 8

What is neuropathic pain and what nerves does it affect?

Answer 8

Neuralgia can affect any of the sensory neres to the orofacial region (trigeminal, nervus intermedius, occipital, glossopharyngeal)

Neuropathic pain is the result of nerve damage and unsuccessful repair.

Question 9

recurrent brief episodes of unilateral electric shock-like pains, abrupt in onset and termination, in the distribution of the nerve that are triggered by innoculous stimuli.

What is this?

What is its cause?

Answer 9

unilateral electric shock-like pains is a description of Trigeminal Neuralgia.

Most of the cases of CN are caused by a compression of a trigeminal nerve root, most commonly branches of the maxillary and mandibular trigeminal divisions.

The compression causes a demelination in a circumscribed area around the compression. The demyelination may lead to cross talk between the fibers that carry discriminative touch and the C-fibers that carry pain.

Question 10

Stabbing pain involving the ear, tonsillar fossa, base of the tongue, and beneath the angle of the jaw.

etiology:

Answer 10

Glossopharyngeal neuralgia

Etiology- can also be cerebellopontine tumor, peritonsillar abscess, carotid aneurysm and Eagle syndrome

**Severe attacks may rarely be associated with bradycardia/asystole resulting in syncope, presumably because input from CNIX into the tractus solitarius has an effect upon the dorsal motor nucleus of X

Question 11

What nerves carry information about taste?

what nerve carries messages about texture, temperature, and pain

Answer 11

CN VII, IX, and X carry information about the four taste modalities

CN V carries messages about texture, temperature, and pain

Question 12

Burning Mouth Syndrome:

etiology:

Answer 12

Burning mouth Syndrome:

etiology: decreased innervation of the anterior taste buds by chorda tympani and an increase in trigeminal innervation.

In idiopathic burning mouth sydrome, it is believed that damage to chorda tympani decreases inhibition on trigeminal afferents innervation the tongue and oral cavity and results in burning pain (activates TRPV1)