Orofacial Pain Flashcards
What is pain?
An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.
What systems can you use to assess pain?
Physical symptoms
PAIN scores (McGill)
Emotional symptoms
Psychological scores (HAD)
QOL scores (OHIP)
What systems in the body regulate pain?
Nociception
Peripheral Nerve Transmission
Spinal Modulation
Central Appreciation
Where in the embryo does the trigeminal nerve develop from?
The 1st pharyngeal arch.
Which structures are innervated by the trigeminal nerve in relation to embryonic development?
Any structures which develop from the first pharyngeal arch.
What causes trigeminal neuralgia?
Idiopathic:
Classical:
Vascular compression of the
trigeminal nerve
Secondary:
Multiple sclerosis
Space-occupying lesion
Others: skull-base bone deformity, connective tissue disease,
arteriovenous malformation
What clinical investigations would you do for suspected trigeminal neuralgia ?
o Trigeminal nerve reflex testing
o Full neurological examination
o OPT to rule out dental cause then MRI brain scan
o Blood tests – FBC, U&E’s. Blood glucose; LFTs
o Positive response to carbamazepine drug management confirms diagnosis
What 2 neurological disorders can give rise to trigeminal neuralgia?
o Multiple sclerosis
o Tumour compressing on trigeminal nerve
What is the first line drug for management of trigeminal neuralgia?
o Carbamazepine modified release 100mg
▪ Send: 20 tablets
▪ Label: 1 tablet twice daily
What blood tests must be done before starting carbamazepine?
o FBC – haematology
o U&Es and LFTs – biochemistry
What are the side effects of carbamazepine?
o Liver dysfunction
o Allergies
o Ataxia
o Nausea, vomiting, dizziness
o Dry mouth and swollen tongue
o Sedation
o Consistent nightmares
What are the 2 indications for surgery for treating trigeminal neuralgia?
o When medical intervention is ineffective or contraindicated
o When medication has adverse side effects
o Seriously affecting quality of life
What types of surgery that can be carried out for trigeminal neuralgia?
o Peripheral neurectomies
o Trigeminal nerve balloon compression
o Microvascular decompression (MVD)
o Radio-surgery gamma knife
Name and describe the two types of orofacial pain syndromes?
Dental:
▪ Generally gets better or worse over time
▪ Usually acute/sub-acute not chronic
Non-dental:
▪ Generally acute infective non-dental pain that gets worse or
chronic pain usually caused by a non dental condition
List the three types of dental pain and how they can arise.
Musculoskeletal = Periodontal and TMJD pain
Visceral structures = Abscesses, pulpal pair, caries
Atypical odontalgia = dental pain without detected
pathology which follows distinct pattern of pain (pain free
episodes with immense pain which settles spontaneously)
What are the features of non-dental neuropathic pain?
Constant burning/aching pain with a fixed location
and intensity
Generally occurs after injury from trauma, XLA,
herpes zoster singles, destructive treatment or
after routine treatment,
List four examples of non-dental neuropathic orofacial pain.
▪ Generally Trigeminal neuralgia
▪ Chronic regional pain syndrome (CRPS)
▪ Traumatic injury to facial nerve
▪ Surgical injury to nerves of the H&N
What is non-dental psychogenic orofacial pain?
Persistent idiopathic facial pain which poorly fits
into standard chronic pain syndromes and responds
poorly to treatment.
Briefly describe the mechanism by which pain occurs.
Tissue damage leads to prostaglandin and bradykinin production
Nociceptors receive these and send signal to spinal chord
Where in the nervous system do local anesthetics AND NSAIDs affect to minimize pain?
Nerve endings.
Where in the nervous system do local anesthetics work to minimize pain?
Nerve endings, primary afferent nerves, dorsal root ganglions.
Where in the nervous system do opioids, a2 agonists, TCAs and SSRIs take affect?
Descending noradrenergic and serotoninergic inhibitory fibers.
