24 - Orofacial pain

Question 1

Define pain.

Answer 1

An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage

Question 2

What can be used to assess pain patients?

Answer 2

• McGill pain score
• HAD psychological score (emotional, hospital anxiety and depression)
• QoL score (OHIP)

Question 3

How is pain passed through the body?

Answer 3

• nociception
• peripheral nerve transmission
• spinal modulation
• central appreciation

Question 4

Describe how the developing embryo affects pain?

Answer 4

• as the embryo develops and structures migrate they take with them the nerve and blood supply
• this is why referred pain can occur in seemingly unrelated areas of the body
• pain does not follow anatomical borders

Question 5

Why does pain refer from some areas of the face to the cervical region?

Answer 5

Trigeminal ganglion is developed from the C1-C3 and also has synapses here

Question 6

Describe a somatic reflex arc.

Answer 6

• stimulus
• sensory afferent neurone
• relay neurone
• motor efferent neurone

Question 7

What is an autonomic reflex arc?

Answer 7

• often causes vaso-motor response
• caused by autonomic pain via autonomic nerves
• associated symptoms (ie vasodilation) indicates which type of nerve is affected

Question 8

What chemical mediators are associated with peripheral nociception?

Answer 8

• 5-HT
• bradykinin

Question 9

What is Melzak and Wall’s principle?

Answer 9

Gate control of pain

Question 10

Describe the gate control of pain.

Answer 10

• pain is felt by the pain fibre and taken to the spinal cord
• if a sensory stimulus is applied to the same area, the sensory fibre also takes this to the spinal cord - this reduces the pain felt

Question 11

What is descending facilitation of pain?

Answer 11

When the brain anticipates pain, it will respond to a painful stimulus at a lower threshold

Question 12

What is descending inhibition of pain?

Answer 12

• battlefield mentality
• brain ignores pain signals due to need for function ie escape

Question 13

What is neuronal plasticity?

Answer 13

• neurones change during chronic pain
• some sensory fibres sprout to join with pain neurones, to stimulate pain on touch rather than a painful stimulus
• makes it easier for pain to pass gate

Question 14

How do you prevent learned pain?

Answer 14

• early management
• peripheral management

Question 15

What peripheral management can be used to prevent learned pain?

Answer 15

• LA
• NSAIDs
• opioids
• gabapentinoids

Question 16

What is CRPS?

Answer 16

• chronic regional pain syndrome
• delocalised pain that spreads beyond anatomical boundaries
• can be bilateral
• feels tight or burning
• associated with autonomic changes such as swelling and heat/change in colour
• can be significantly disabling