Orofacial Pain

Orofacial Pain

1. "An unpleasent sensory and emotional experience, associated with actual or potential tissue damage or described in terms of such damage"

2. Pain is Multi dimensional

   • Feel location
   • Feel intensity
   • Feel type
   • If Pt feels it, it's real!

3. Clinical terms

   • Analgesia
     • Absence of pain in responce to stimuli, when it should hurt
     • Lack of pain
   • Hyperalgesia
     • Exacerpated pain produced by stimuli, when pain should be mild
   • Allodynia
     • Painful on stimulation when it shouldn't
   • Sedation
     • Reduction in irritabilty/aggitation
   • Anaethesia
     • Lack of feeling
     • Analgesia
     • Amnesia
     • Immobilisation

4. Acute Pain

   • <30 days

5. Cronic Pain

   • > 6 months
   • Or, Pain that lasts longer than the expected period of healing

6. Subacute Pain

   • 30 days-6 months

7. Acute Nociceptive

   • Nocicoreceptors
     • are pain receptors
   • Pain is localised, constant, aching, throbing
   • Treat with painkillers

8. Cronic Neuropathic Pain

   • 1 in 10 of pupulation
   • Treat with antidepresents

9. Pain Transduction

   • Primary afferent Axons
     • C fibres
       • Unmylenited
         • Pain, temerature and itch related
     • Mylenated
       • A-Alpha
         • Fastest/Thickest
           • Proprioceptive (muscle sense)
       • A-Beta
         • Touch related
       • A-Delta
         • Pain and temerature related
     • Noxious/Nocioreceptors
   • Propagation of Pain
     • Specificity
       • From stimuli, along one pathway to brain
     • Pattern Thoery
       • Any sensory receptor, over time/area. Touch,pressure, vibration could over stimulate the small pain fibres, hense rubbing the site
     • Gate controled Theory?
       • Stimuli of T-cells?T-cells 'Gate of pain'?
     • Dimensions
       • Cognitive reasoning/pscological aspect
     • Thoery today
       • still not sure, Specificity and Dimensions still hold strong
     • Theories on pain
   • Sensitisation
     • Progressivly amplified stimulus will start warm, the pain
     • Peripheral sensation
       • First stimulus, activates high threshold receptors that lead to pain
         • After tissue damage, nerve endings are in a 'soup' of stimulating chemicals, which then lower threshold and cause pain
     • Central Sensitisation
       • Stimulation from surrounding areas (of injury) excite the spinal cord, resulting in pain. Analgesics after surgery will help this.

10. Stimulus evoke pain

    • Mechanical Stimuli
      • Pressure (pain threshold)
    • Thermal Stimuli
      • C-Fibres
        • Hot 42oC
          • Cold will hurt after while
    • Chemical stimuli
      • Chemicals in cooking
        • Stimulate Noxious
          • Results in pain
    • Electrical stimuli
      • Pain varies with intesity

11. Clinical presentations of pain

    • Transient orofacial pain
      • richly innervated
        • Can have pain easily
    • Pain from tissue injury
      • Peridontitis
        • Tooth pulp etc
    • Nervous system pain
      • Trigeminal Neuralgia
    • Idiopathic Pain
      • TMJ/Muscle/aches
    • Migraines