Oro facial pain

OROFACIAL

PAIN

Thilanka Umesh Sugathadasa

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Physiological basis for the pain

Definition for the pain by IASP

Pain is an unpleasant sensory or emotional experience associated with actual or potential

tissue damage, or describe in terms of such damage.

Nature of pain

Subjective Modified by the Cultural/ Behavioural/ Personality/ Developmental factors

Protective

It is a symptom

Associated with crying/ sweating/ BP/ HR increase

Having dual nature

Fast pain Slow pain

Acute

Pricking type

Short duration

Well localized

Thin myelinated A delta nerve fibers are involved.

Chronic

Throbbing type pain

Poorly localized.

Long duration

Unmyelinated c nerve fibers are involved

Classification on the basis of pain

Nociceptive pain- Stimulation of the nociceptors due to

Chemical

Thermal

Mechanical events that has the potential to damage the body tissues.

Pain

Duration(Acute/ Subacute & chronic)

Anatomy(Headache/ chest pain)

Mechanism

somatogenic (axis i)

Nociceptive

Superficial

Somatic

Deep

Somatic Visceral

Neuropathic

Episodic Continuous

psychogenic (Axis ii)

Quality(Sharp/ burning/ tight)

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Neuropathic pain- damage to the nerves system itself cause the neuropathic pain

Two types

- Peripheral neuropathic pain (Damge to the peripheral nerves)

- central neuropathic pain(Damage to the brain/ brain stem/ spinal cord)

Above two are mainly somatogenic pain, psychogenic pain is that caused, increased or

prolonged by Mental / Emotional/ Behavioural factors

Superficial somatic pain

1. Cutaneous pain

2. Mucogingival pain

Caused by mainly injury to skin or superficial tissues.

Cutaneous nociceptors terminates just below the skin & They are present in higher

concentrations so produse fast pain. Due to those reasons most of the time cutaneously minor

wounds & minor burns(1st degree.) present,

No CNS excitatory effects.

LA at the site can abolish pain.

Deep somatic pain

1. Musculoskeletal pain

- Periodontal pain

- Osseous pain

- Muscular pain

- TMJ pain

- CT pain

Most of the time dull pain

Originates from ligaments, Tendons, Muscles, Bones, Blood

vessels & fascia.

Detected with somatic nociceptors, but due to the scarcity

of the pai receptors it causes dull, poorly localized pain on

longer duration than the cutaneous pain.

Eg- Broken bones/ Myofascial pain.

Pain response not always corresponds to the site &

intensity of the stimulus

CNs excitatory effects are common

Local anaesthetic block can eliminate the pain.

TMJ pain

Capsular pain(capsulitis)

Synovial pain (Synovitis)

Retrodiscal pain (Retrodiscitis)

Ligamentous pain

Arthritic pain

Muscular pain

Protective core contraction

Local muscle soreness

Myofascial pain

Myospasm

Centrally mediated myalgia

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Deep visceral pain

1. Pulpal pain

2. Vascular pain

3. Neuro vascular pain

4. Glandular pain

5. ENT pain

6. Occular pain

7. Visceral mucosal pain

Originate from body’s viscera, or organs. Visceral nociceptors are located within the body organs

& internal cavities.

The even greater scarcity of nociceptors in these areas produces pain that is usually more aching

or cramping & of a longer duration than somatic pain.

Visceral pain may be well localized, but often it is extremely difficult to localize, & several

injuries to visceral tissues exhibit “reffered” pain, where the sensation is localized to an area

completely unrelated to the site of injury.

Pain has no relationship for the biomechanical activity.

Pain does not arise until threshold of stimulus is attained.

process involved in nociception

1. Transduction – process of converting noxious stimuli to action potentials.

2. Perception – Central processing of nociceptive pain in order to interpret pain.

Stimuli – Chemicals/ electrical / Thermal/ physical

Neuropathic Pain

Spontaneous or triggered by non-noxious stimulus.

Does not corresponds to the intensity of the stimulus.

No evidence of tissue damage.

Episodic(Intermittent or paroxysmal pain)

Continuous pain

Paroxysmal neuralgias -Trigeminal neuralgias -Glossopharyngeal neuralgias - Geniculate neuralgia - Superior laryngeal neuralgias - Nervous intermedius neuralgia

Neurovascular pain(Overlaps to some extent with deep visceral)

Centrally mediated - Atypical odontalgia(Phantom pain) - Post- herpetic neuralgia - Burning mouth syndrome - Chronic regional pain syndromes

Peripherally mediated - Neuritic pain(Herpes zoster/ Peripheral Neuritis) - Differentiation pain(Traumatic neuroma) - Entrapment neuropathy

Sympathetically maintained pain - Causalgia (pain arising on an operating site eg-

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after extraction ) - Reflex sympathetic dystrophy

Metabolic polyneuropathies

Rapid, Piercing, electric type of pain

Incapacitating, very severe pain

Short duration

No pain between episodes

Pain occur in the distribution of the concerned nerve

No evidence of tissue damage.

Dull, burning pain

Ongoing pain without remission

Intensity can vary

Additional neurological signs may be presents(Loss of sensation, Paresthesia)

No evidence of tissue damage

Causes (Origin) of orofacial pain

1. Dental pain – Pain from dentine, pulp, periapical periodontal tissues, gingivae, lateral

periodontal tissues, tooth socket.

2. Pain arising from the mucosa(Labio buccal, lingual, floor of mouth & palate)

3. Pain arising from the jaw bone

4. Pain arising from temporomandibular joints & masticatory muscles.

5. Pain arising from the salivary glands & ducts

6. Pain arising from the maxillary & other sinuses.

7. Neuralgic pain- Neuropathic pain

8. Vascular pain – From cranio facial & blood vessels

9. Referred pain – Cervical spine, eyes, heart

10. Psychogenic pain- tension headache & other headaches, Atypical facial pain, Burning mouth

syndrome, Atypical odontalgia.

Dental pain

Exposure of Dentine

- Dentinal caries

- Fracture of tooth

- Cracked tooth syndrome

- Attrition of tooth

- Abrasion/ Erosion

Pulpitis

Apical periodontitis & Apical abscess

Periodontal abscess

ANUG

Desquamative gingivitis

Pericoronitis

Alveolar osteitis(Dry socket)

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Mucosal pain

Traumatic ulcers

Apthous ulcers

Erythema migrans(Tongue)

Foliate papilitis (Tongue)

Oral LP

Oral submucous fibrosis

DLE

Erythema multiforme

Malignancy

Radiation induced mucositis

Neuralgic pain

1. Trigeminal neuralgia

2. Glossopharyngeal neuralgia

3. Post-herpatic neuralgia

Pain arising from maxillary & other sinuses

1. Acute maxillary sinusitis

2. Frontal sinusitis

3. Ethmoidal sinusitis

4. Chronic maxillary sinusitis

Pain from jaw bones

1. Fracture of the jaw(Mandible/ zygoma/

Maxilla)

2. Osteomyelitis of mandible

3. Osteoradionecrosis

4. Bisphosphonate induced osteonecrosis

Pain arising from the salivary glands

1. Not all pathologies if salivary glands

cause pain.

2. Acute parotitis including recurrent

juvenile parotitis.

3. Mumps

4. Submandibular sialadenitis

5. Sialolithiasis

6. Sialodochitis(Infection of the duct)

Vascular pain

1. Migraine

2. Migranous neuralgia

3. Temporal(cranial arteritis)

Headaches

1. Tension headache

2. Other headache

Management of Orofacial pain

Mx of Dental pain

Mucosal pain is on other notes

Differential diagnosis from non-odontogenic

pain

1. TN

2. TMJ pain & pain of muscle origin

3. Maxillary sinusitis pain

4. Salivary gland pain

5. Migraine & migranous neuralgia

6. Glossopharyngeal neuralgia

7. Post herpetic neuralgia

8. Atypical odontalgia

9. Temporal arteritis

10. Oral dysaesthesia or burning pain in the

mouth.

11. Burning mouth syndrome

12. Atypical facial pain

TN

1. A characteristic neuropathic pain in the

distribution of one or more branches of

the fifth cranial nerve.

2. It occurs in paroxysms, with each

episode lasting from a few seconds to 2

minutes.

3. Frequency of paroxysms varies from

hundreds of attacks a day to long

period.

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Primary TN

TN Epidemiology Aetiology

Between successive episodes of pain, the patient is pain free.

A severe pain that is intense, sharp, superficial, stabbing, shooting, incapacitating & often like an electric shock.

In a single pts different attacks of the pain have the same character.

Pain provokes brief muscle spasm of the facial muscles, thus producing tic- patient grimaces with contortion of the face.

Light touch in a specific area or talking, washing the face or brushing the teeth may trigger an attack.

No neurological deficit can detectable.

Incidence in the UK 27 cases per 100,000 persons in the population.

Previous studies USA 6/100,000 women’s & 3.5/100,000 men’s in a F:M ratio of 1.75:1

In men aged>80 incidence is 45.2/100,000

More common after the age of 40

Right side of the face is more commonly affected than the left.

Idoipathic – 90%

Compression Blood vessels may press on the trigeminal nerve as it leaves the brainstem at its nerve root in the cerebello-pontine angle. Compression of the nerve leads to demyelination resulting in spontaneous generation of the electric impulses.

Degeneration Some have postulated it to be part of the aging process, as with increasing age the brain atrophies, leading to redundant arterial loops which can cause compression.

Myelin sheath infiltration In tumor or Amyloidosis

Secondary (Symptomatic) TN

Atypical TN Pre TN

Cerebello- pontine angle tumor may cause compression in some pts (Younger patients)

Multiple sclerosis: 2-3% of patient with TN may have MS

Hypertension is a risk factor (More in females)

Without treatment, typical TN (TN1) may transform over time to become atypical TN (TN2).

A change in the character of the pain occurs to more constant & background pain & the development of sensory impairment.

Therefore, some authorities recommend early intervention to give the opportunity of pain relief without sensory deficits.

There are some reports of the existence of a pain condition termed pre TN.

Patients who subsequently develop typical TN may experience a prodromal pain termed “Pre TN”.

The prodromal pain is experience as a toothache or sinusitis like pain lasting up to several hours sometimes triggered by jaw movements or by drinking hot or cold liquid.

Typical TN develops a few days to several years later, and in all cases affected the same division of the trigeminal nerve.

This becomes pain free when using carbamazepine or baclofen.

Recognition avoids unnecessary irreversible dental procedures.

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Diagnostic criteria for classical TN

A. Paroxysmal attacks of pain lasting from a fraction of a second to 2 minutes, affecting one or

more divisions if the trigeminal nerve & fulfilling criteria B-C.

B. Pain has at least 1 of the following characteristics:

Intense/ Sharp/ Superficial/ Stabbing/ precipitated from trigger areas or by trigger factors.

C. Attacks are stereotyped in the individual pts.

D. There is no clinically evident neurological deficit.

E. Not attributed to another disorder.

Diagnosis of TN

1. History

2. Clinical examination to rule out other pathology including dental causes.

3. Cranial nerve function test

4. Diagnosis is conclusive if one or more attacks occur during history taking or clinical examination

when clinician can witness the “tic”

5. MRI to rule out the tumors in the cerebello- pontine angle mostly in young patients and

medically uncontrollable cases.

Treatment of trigeminal neuralgia.

Pharmacological Surgical intervention

1. Single drug therapy 2. Multiple drug therapy in “breakthrough pain” - Carbamazepine/ oxcarbazepine is the mainstay of

treatment. - Other drugs (usually in combination) in

breakthrough pain or when carbamazepine is contraindicated.(Valproate/ phenytoin/ clonazepam/ gabapentin/ lamotrigine/pregabalin/ baclofen etc)

- Carbamazepine is started at a low dose: 100mg bd or 8 hourly & increased gradually to obtain optimum response with or without amitriptyline.

- Side effects (Dizziness) may affect compliance. - Serious adverse effects have to be watch

Older methods 1. Peripheral (Inferior alveolar, mental, & infra

orbital branch resection) - considered less effective.

2. Gasserian ganglion procedures- Alcohol/ phenol injections now largely abandoned.

3. Nerve root procedures- Wide sectioning of roots – rhizotomy Newer methods

1. Percutaneous procedures 2. Stereotactic radiosurgery or radiotherapy. 3. Posterior fossa exploration & micro vascular

decompression (MVD) of the trigeminal root(more surgical morbidity, however)

Prognosis of TN

- 1/3 of patients will have mild symptoms.

- Some pts only ever have one episode

- Many peoples have period of remission with no pain for months or years.

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- Unconfirmed evidence that in many people it becomes more severe & less responsive to treatment

with time.

Condition Factors

Maxillary sinusitis

Can be unilateral or bilateral, felt on the face

Acute or chronic stage of sinusitis

Dull ache exacerbated by head movements particularly lowering the head- more in bilateral than in unilateral.

Pain may be felt in the maxillary teeth. TTP may present mostly in acute

Nasal congestion may be present.

Occipitomental radiograph may reveal radio opacity/cloudiness of the maxillary sinus(es) A fluid level may be seen in the acute maxillary sinusitis. Mx

Mostly medical

Antibiotics given mainly for the chronic sinusitis.

Nasal decongestant

Antihistamines

Steam inhalation

Functional endoscopic sinus surgery (FESS) by ENT surgeons

Migraine

A neurovascular pain sometimes proceeded by visual or sensory aura

Throbbing or pulsatile pain

Localized in the fronto-temporal & ocular area, but can be felt anywhere around the head.

Photophobia or phonophobia may be found

Nausea & vomiting may occur

DD of TN

Migranous neuralgia(Cluster headache)

Nuerovascular pain

No aura

Severe pain, strictly unilateral, retro orbital or periorbital radiating to the jaws sometimes.

May be confused with TN(but consider as worse than the TN. Because each attack last longer than in the TN)

Accompanied by ipsilateral lacrimation, conjunctival injection, nasal discharge or congestion

Each cluster is consists of 8 attacks per day or less during sleep or early morning hours.

Attacks lasts from 5-100 minutes to few hours.

Glossopharyngeal neuralgia

Repeated episodes of severe unilateral pain in the following areas which can lasts from a few seconds to few minutes with similar characteristics as TN Back of the nose & throat Back of the tongue Ear Throat Tonsil area Voice box(Larynx)

Management on similar lines as for TN

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Atypical Odontalgia

A form of tooth ache present in apparently normal teeth.

Intra oral equivalent of atypical facial pain.

Generally dull pain, often moves from one tooth to another – lasts for period of 4 months to several years.

Cause is not yet clear

Diagnosis by exclusion.

Rx is tricyclic or other types of antidepressants.

Temporal arteritis

Commonest form of giant cell arteritis affecting the Head & Neck blood vessels.

An autoimmune disease.

Affects mostly superficial temporal artery & ophthalmic branch.

Affects mostly the elderly.

Insidious in development over weeks/ months commonly presents as headache in the temporal region with tenderness along the course of the artery.

Jaw pain brought on by chewing/ talking due to ischemia of masseters.

Risk of blindness due to ophthalmic artery involvement.

Diagnosis may require temporal artery biopsy.

ESR or C - reactive protein is very highly elevated.

Treatment is by steroids/ immunosuppressive therapy.

Oral dysaesthesia or Burning pain in the mouth.

Due to clinically identifiable pathology. Ulcerations OSMF

Due to causes that are not visible in the mouth Dry mouth Deficiency of hematinic Drugs eg captopril DM Depression

Burning mouth syndrome

This term is not applied for burning sensation due to identifiable causes except in association with psychogenic depression.

However it is also considered a continuous neuropathic pain

A diagnosis by exclusion

Patient should be handle with empathy.

Rx is by counseling & antidepressant therapy

Atypical facial pain

Not attributed by any identifiable causes.

Diagnosis by exclusion

Patient should be handle with empathy.

Rx is counseling & antidepressants.

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