Complications of 3rd Molar Extractions Flashcards

1
Q

Minor complications?

A
- Pain, swelling, trismus
– Infection
– Fracture
– Bleeding and bruising
– TMJ problems
– Temporary nerve damage
– Periodontal problems
– Damage to other teeth
– Oral-antral communication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is guaranteed after surgical removal of lower 8s?

A

Pain - can be severe
- Pre-op - warn pt, analgesic advice (ibuprofen probs best)

Swelling and trismus

  • Variable but can be marked
  • Warn pt
  • Advice on how to minimise - NSAIDS

Infection

  • Difficult to assess incidence as diagnosis not always straight forward
  • Higher incidence of post op infec in lower 3rd molar sockets
  • Good OH post op
  • No good evidence for routine use of antibiotics
  • Consider all variables - antibiotics have a role - co-morbidity, local and systemic
Damage to adjacent teeth 
- Mobilisation of 2nd molars
- Damage to restorations
- Fracture of adjacent teeth 
Pre-op 
- Assess clinically and radiographically 
- Warn pt
- Have plan in place to minimise risk and deal with complication

Fractured mandible

  • Elderly, edentulous pts with atrophic mandible
  • Pre-existing bone pathology
  • Large bone defects
  • Excessive use of force
  • Cryers, large elevators

Upper 8s - oral-antral communication, fractured tuberosity. have a retractor around the back to ensure 8 doesn’t go into the pterygomandibular space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When can trigeminal nerve injuries occur?

A
Removal of wisdom teeth
Implantology, trauma, soft tissue surgery 
Needle stick (neuropraxia)
Endodontics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Incidence of nerve injury after 3rd molar removal? - lingual and IAN
V IMPORTANT

A

IAN

  • Temporary 5-7%
  • Permanent 0.5-1%

Lingual

  • Temporary 3-7%
  • Permanent 0.3-0.5%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why so many nerve injuries?

A

Proximity of lingual nerve to lower 3rd molars

  • Mainly drill injuries
  • Still lingual flaps being raised - retractor can crush the nerve or not be correctly positioned to protect the lingual nerve
  • Increase lingual nerve injuries - coronectomy?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The effect of trigeminal nerve injury?

A

Loss of sensation of anterior half tongue and/or chin/lip
Paraesthesia - reduced sensation
Dysaesthesia - pain, tingling, burning when touched
Allodynia - painful repose to non painful stimuli
Loss of tastebuds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do pt’s with nerve injuries complain of?

A
Pain, unpleasant burning and tingling - electric shock, 24/7
Feel like they're dribbling
Bite their lip
Avoid eating in public
Do not enjoy kissing
Bite their tongue 
Tongue feels like a large lump of jelly 
Lose food under their tongue 
Do not enjoy food
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Management of lingual nerve injuries -

A

• Lingual flap raised and lingual periosteum divided
• The central and distal nerves stumps identified and
mobilised
• The damaged segment of nerve (4-14mm mean 9.5mm)
was excised
• Direct reapposition with 5-10 (mean 7) 8/0 ethilon
epineurial sutures
• All patients given dexamethasone and antibiotics
• Initial study prospective, quantitative assessment of 53 patients pre-op and >12 months post-op

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What outcomes are measured after lingual nerve repair?

A
  • Light touch
  • Pin prick
  • Two point discrimination
  • Gustatory response
  • Altered sensation – dysaesthesia
  • Subjective assessment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Effect of lingual nerve repair?

A
Majority of pts regain some sensation
Fewer pts tend to bite their tongue 
Significant improvement was shown in tests using:
- Light touch stimuli
- Pin prick stimuli
- Gustatory stimuli
- 2 point discrimination

Pt consider it worthwhile
It will never return to normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Causes of IAN injury?

A

Proximity of lower 3rd molars
Increasing due to implant placement
Some from trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Management of IAN injury following 3rd molar removal?

A

Immediate repair at the time of third molar removal?
• The nerve is usually well supported in the mandibular canal
• Even after transection the ends do not usually retract
• Primary repair is not normally required
• Control bleeding with temporary packing with gauze

AVOID
• Diathermy
• Whitehead’s varnish and other medicaments
• Surgicel
• Bone wax
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Injuries from implantology?

A

Can be from drill or implant
Many drills longer than implant length (can be 1.5mm longer)
Overdrilling - in low resistance bone - slippage of drill, pressing at roof of canal
Miscalculation of position of IAN
Immediate placement - more likely to cause IAN
Safety zone 2-4mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What area is at high risk?

A

Mental foramen area
Mental foramen 4mm anterior to ensure avoidance of anterior loop
Consider surgical exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Intraoperative factors when you get the nerve?

A

• ‘Sudden give’
• ‘Electric shock’
• Arterial bleed – large percentage of injuries – secondary
to haematoma
• May be sensible to wait 2 days and then place implant –
avoid compression ischemia
• No evidence though!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Management post injury of IAN due to implant?

A

Good evidence that neural recovery with implant related injuries, inversely proportional to time
Ideally remove implant within 24-36hrs
Postoperative call - same day or following day

  • Short-term remove implant
  • Inform patient
  • Take radiograph for localisation of lesion
  • Evaluate – time elapsed, proximity of implant etc
  • Neurosensory evaluation
17
Q

Indications for surgical intervention?

A

Persistent anaesthesia

Dysaesthesia/pain

18
Q

What to do when IAN decompression/neurolysis?

A
Cannot excise complete segment
• Can remove bony obstruction
• Can remove bony compression
• Can remove remove soft tissue tethering/tension
• Can remove ‘neuroma’ - ê dysaesthesia
19
Q

When to do when pt has complete anaesthesia?

A

Nerve Graft - someone elses nerve is used

20
Q

What can IAN decompression result in?

A
Reduces number of pts with dysaesthesia 
Signif improves level of sensation
Level of improvement is modest
Gives no improvement in some pts
Never results in complete recovery 
We cannot predict who will benefit 

ONLY OFFERED TO PTS WITH SEVERE SYMPTOMS

21
Q

Incidence of permanent nerve injury following nerve block?

A

1 in 20,000 and 1 in 850,000

22
Q

Direct trauma from LA?

A

Face bevel laterally

Most nerve injuries caused by LA injections - multiple injections

23
Q

Articaine vs lignocaine for IAN injuries?

A

Avoid articaine for IAN as most lignocaine injuries recover

Articaine IAN block’s are high risk for permanent dysaesthesia

24
Q

Endodontics cause IAN damage by?

A

Apex near nerve and RCT is overextruded - Need to clean the nerve as obturation is a chemical insult to it

25
Q

How to minimise nerve damage?

A
IAN injuries usually drill injuries
Some are crush injuries - following forceps extraction
Low threshold for sectioning 
Avoid forceps
Elevator removal preferable 
Avoid lingual flaps/retraction
26
Q

Radiographic assessment

A
• Type of impaction
• Depth of tooth within bone
• Crown form
• Root form and number
• Coronal or root pathology
• Other pathology (cyst, caries in 2nd molar)
• Relationship with mandibular canal (IAN) or
maxillary sinus
27
Q

What to assess with the IAN?

A
Radiolucency 
Deviation/constriction
Loss of cortication
Deviation of root 
Narrowing of roots
28
Q

CT scan?

A

Not routinely indicated
May be appropriate in high risk cases
CBCT

29
Q

Coronectomy?

A
Controversial 
Pros and cons
Medico-legal issue
Should document discussed with pt if high risk of IAN damage
Pt choice