The document discusses the classification of nerve injuries, primarily focusing on traumatic causes and medical procedures leading to such injuries, categorized by Seddon's and Sunderland's classifications. It elaborates on symptoms, evaluation methods, and management strategies, including both medical and surgical interventions for different types of nerve damage. Post-operative protocols and nerve regeneration techniques, along with their implications on recovery, are also highlighted.

1. CLASSIFICATION OF NERVE
INJURIES
KEERAT KUCKREJA
150301176
IV YEAR

2. ETIOLOGY
• Trauma is the major cause of nerve injuries
• Iatrogenic errors
• Delivery of LA
• Oral surgical procedures
• Endodontic procedures
• Periodontal surgeries
• Chemical agents
INFRAORBITAL NERVE
• Lefort II and Lefort III level osteotomies
• Caldwell luc procedure
• Orbital osteotomies
• Fractures of midface and orbit

3. LINGUAL NERVE
• Mandibular third molar removal
• Excision of submandibular and sublingual
glands
• Iatrogenic instrumentation of floor of mouth
• Mandibular tumor removal
• Osteotomies
INFERIOR ALVEOLAR NERVE
• Removal of any impacted mandibular tooth
• Endosteal implant placement
• Mandibular osteotomies
• Mandibular cyst and tumor removal
• Mandibular resection
• Orthognathic and preprosthetic surgeries

4. ANATOMY OF PERIPHERAL NERVE

5. SEDDON’S CLASSIFICATION (1942)
SEDDON CLASSIFIED NERVE INJURIES
INTO ACC TO THE AMOUNT OF
NERVE TISSUE DAMAGED AND
TISSUE STILL INTACT:
• NEUROPRAXIA
• AXONOTMESIS
• NEUROTMESIS

6. NEUROPRAXIA:
• Mild temporary injury due to compression or retraction of nerve
• There is a conduction block due to anoxia from the interruption of epineural or
endoneural blood supply causing intrafasicular edema
• No axonal degeneration distal to the site of injury
• Temporary conduction block (sensory loss)
• Spontaneous recovery within 4 weeks
• No surgical intervention required

7. AXONOTMESIS:
• Disruption or loss of continuity of some axons , which undergo Wallerian
degeneration distal to the site of injury
• General structure of the nerve remains intact
• Prolonged conduction failure
• Intial signs of recovery do not appear until after 1-3 months
• Eventual recovery less than normal (paresis and hypoesthesia)
• Sensory nerve injuries may develop persistent painful sensation (dysesthesia)

8. NEUROTEMESIS:
• Complete severance of all the layers of the nerve
• Total permanent conduction blockade of all the impulses (paresthesia, anesthesia)
• The discontinuity between the proximal and the distal segment is filled up with scar tissue
• No recovery without surgical intervention

9. SUNDERLAND’S CLASSIFICATION (1978)

10. STAGES OF NERVE HEALING

11. CLINICAL FEATURES
• Deep seated pain
• Diffuse and continuous in nature
• Functional loss if motor nerve is involved
• Drooling
• Tongue biting
• Thermal burns
• Changes in speech
• Swallowing
• Taste perception alterations
• The area supplied by the sensory branch may become hyperesthetic of
hypoesthetic.

12. EVALUATION
• Ascertain patient’s main complaint:
• regarding loss of sensation
• Pain
• Abnormal sensation or functional impairment
• Patient’s history:
• Trauma or surgical procedure associated with injury
• Date of incident
• Progress of symptoms
• Progress of recovery:
• Excellent prognosis: return of sensation within first 4 weeks (neuropraxia)
• Fair prognosis: return within 1-3 months ( axonotmesis)
• Poor prognosis: lack of recovery for 12 weeks or longer (neurotmesis)

13. CLINICAL NEUROSENSORY EXAMINATION:
• Static light touch
• Brush directional discrimination
• Two point discrimination
• Pin pressure nociceptive discrimination
• Thermal discrimination
STEP 1: MAP THE AREA OF SENSORY DISTURBANCE

14. 1. STATIC LIGHT TOUCH :Performed using Von Frey filaments
2.BRUSH DIRECTIONAL DISCRIMINATION : Performed using camel hair brush

15. 3.TWO POINT DISCRIMINATOR
4.PIN PRESSURE NOCICEPTION

16. 5. THERMAL DISCRIMINATION
6.LOCAL ANESTHETIC NERVE BLOCKS :
Failure to relieve pain in the presence of effective nerve block suggests a central
sympathetic or psychological rather than a peripheral cause of dysesthesia

17. MANAGEMENT
• MEDICAL MANAGEMENT:
Topical Anesthetics 5% viscous lidocaine
gel
NSAIDS Ketoprofen 10-20%
PLO base
Sympathomimetics Clonidine 0.01% PLO
base or patch
Anticonvulsants Carbamazepne 2% PLO
base
TCA Amitriptyline 2% PLO
base
Topical medications Systemic Pharmacological
Agents
Local anesthetics
Corticosteroids
NSAIDS
Antidepressants
Muscle relaxants
Benzodiazepines

18. • SURGICAL MANAGEMENT:
Indications for Microneurosurgery Contraindications for Microneurosurgery:
Observed nerve severance Central neuropathic pain
Total anesthesia beyond 3 months Dysesthesia not abolished by the LA nerve block
Dysesthesia beyond 4 months Improving sensation
Sever hypoesthesia without improvement beyond 4
months
Medically compromised patient
Excessive delay after injury
PRINCIPLES OF MICRONEUROSURGERY
• Controlled General anesthesia
• Visualization
• Magnification of surgical field
• Good hemostasis
• Removal of pathological tissue or foreign material
• Proper alignment
• Coaptation of proximal and distal nerve stumps
• Suturing without tension

19. SURGICAL APPROACH

20. IN CASE OF WIDER GAPS
NERVE REGENRATION
• An Autogenous nerve graft
is interposed between
nerve stumps to eliminate
tension
• The Great auricular and
the Sural nerves are
common donors
• Short span (1-3cm) nerve
gaps can be repaired with
guided nerve regeneration
• Axonal growth directed by
a tube made up of
alloplastic materials or
autogenous tissues
• The peripheral nerve guidance conduit is surgically implanted, the proximal
and the distal nerve stumps are sutured into the conduit,
• This creates a physical guiding pathway for nerve growth as well as a reservoir
of growth factors that further guide the sprouting daughter axons in the
proximal nerve stump

21. POST OPERATIVER MANAGEMENT
• Standard protocols are followed regarding
antibiotics, analgesics, fluids and discharge
• The neck sutures are removed at 5-7 days after
surgery and leg sutures after 10 days
POST OPERATIVE COURSE
• Variable period of complete anetgesia ,sometimes upto 3 months
• Regrowth occurs at 3mm/day ,that means 3 cm in 1 month
• Dysesthesia is always possible after nerve surgery
• Best prognosis for an anesthetic nerve operated on within 3 months

22. BIBLIOGRAPHY
1.Tubbs RS , Rizk E, Shoja MM, Loukas M, Barbaro N, Spinner RJ, Nerves
and Nerve injuries
2. Trigeminal nerve Injury and Management , Kristopher Lee (OMFS ,
mount Sinai hospital
3. Nilima Malik text book for oral surgery
4. Google images