List 3 possible aetiologies associated with trigeminal neuropathic pain

  1. Post dental/ surgical trauma (Post traumatic trigeminal neuropathy)
    1. third molar surgery , dental implants, local anesthetic injections
  2. Post-macrotrauma
    • road traffic accident/blunt facial truams
  3. Painful trigeminal neuropathy attributed to acute herpes zoster

Describe the key clinical features that distinguish trigeminal neuropathic pain from other orofacial pain conditions

  1. Anatomically confined and unilateral
    • maps to the dermatome of the affected nerve
    • rarely crosses the midline though it may diffuse over time
  2. Peristence of pain beyond the expected healing period (> 3 months post procedure)
  3. Mixed positive and negative sensory signs
    • Positive: allodynia , hyperalgesia, paraestheis
    • negative : hypoesetheis/ numpness or hyopalgesia

Describe the diagnostic approach and investigations required

  • Detailed pain history — onset/timeline relative to the procedure, character/quality, severity (NRS 0–10), distribution, and aggravating/relieving factors.
  • Comprehensive intraoral examination — inspect the extraction socket for infection/dry socket/healing complications and assess adjacent teeth and soft tissues.
  • Cranial nerve sensory examination — bedside testing of the IAN and lingual nerve territories using light touch, pin-prick, and two-point discrimination.

3 pharmacological managements

  • Tricyclic antidepressants like amitriptyline, nortriptyline
  • Gabapentinoids
    • gabapentin, pregabalin
  • Anticonvulsants like carbamazepine

Identify 3 psychosocial factors relevant to the management of this patient

  • Depression/ low mode
  • Pain catastrophising (thiking of the worst-case scenario)
  • Reduced quality of life and coping efficacy

List 3 non-pharmacological strategies that may be used in the management of trigeminal neuropathic pain

  • Patient education and reassurance
    • explain the neuropathic mechnism and set realistic expectatoins (a 50% pain reduction is a success; 100% cure is rare )
  • Cognitive behavioural therapy and pain neuroscience eduction
    • address catastrophising
  • Orofacial physiotherapy/ sensory re-education and TENS (transcutaneous electrical nerve sitmulation )

Outline 3 potential complications or challenges encountered with long-term management of trigeminal neuropathic pain

  • Post traumatic trigeminal neuropathic pain is characterised by a poor outcome/ progrnosis and can even progress to central sensitization
  • Limited and side-effect-laden response to pharmacotherapy
    • effective relief often requires high drug doses
    • have to balance efficacy and tolerance and side effects
  • Narrow window for improvement / incomplete sensory recovery
    • sensory deficits may be permanent
    • referral after 13 months significantly reduces the chance of improvement