Complications of 3rd Molar Extractions Flashcards
Minor complications?
- Pain, swelling, trismus – Infection – Fracture – Bleeding and bruising – TMJ problems – Temporary nerve damage – Periodontal problems – Damage to other teeth – Oral-antral communication
What is guaranteed after surgical removal of lower 8s?
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
When can trigeminal nerve injuries occur?
Removal of wisdom teeth Implantology, trauma, soft tissue surgery Needle stick (neuropraxia) Endodontics
Incidence of nerve injury after 3rd molar removal? - lingual and IAN
V IMPORTANT
IAN
- Temporary 5-7%
- Permanent 0.5-1%
Lingual
- Temporary 3-7%
- Permanent 0.3-0.5%
Why so many nerve injuries?
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?
The effect of trigeminal nerve injury?
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
What do pt’s with nerve injuries complain of?
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
Management of lingual nerve injuries -
• 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
What outcomes are measured after lingual nerve repair?
- Light touch
- Pin prick
- Two point discrimination
- Gustatory response
- Altered sensation – dysaesthesia
- Subjective assessment
Effect of lingual nerve repair?
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
Causes of IAN injury?
Proximity of lower 3rd molars
Increasing due to implant placement
Some from trauma
Management of IAN injury following 3rd molar removal?
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
Injuries from implantology?
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
What area is at high risk?
Mental foramen area
Mental foramen 4mm anterior to ensure avoidance of anterior loop
Consider surgical exposure
Intraoperative factors when you get the nerve?
• ‘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!
Management post injury of IAN due to implant?
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
Indications for surgical intervention?
Persistent anaesthesia
Dysaesthesia/pain
What to do when IAN decompression/neurolysis?
Cannot excise complete segment • Can remove bony obstruction • Can remove bony compression • Can remove remove soft tissue tethering/tension • Can remove ‘neuroma’ - ê dysaesthesia
When to do when pt has complete anaesthesia?
Nerve Graft - someone elses nerve is used
What can IAN decompression result in?
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
Incidence of permanent nerve injury following nerve block?
1 in 20,000 and 1 in 850,000
Direct trauma from LA?
Face bevel laterally
Most nerve injuries caused by LA injections - multiple injections
Articaine vs lignocaine for IAN injuries?
Avoid articaine for IAN as most lignocaine injuries recover
Articaine IAN block’s are high risk for permanent dysaesthesia
Endodontics cause IAN damage by?
Apex near nerve and RCT is overextruded - Need to clean the nerve as obturation is a chemical insult to it
How to minimise nerve damage?
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
Radiographic assessment
• 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
What to assess with the IAN?
Radiolucency Deviation/constriction Loss of cortication Deviation of root Narrowing of roots
CT scan?
Not routinely indicated
May be appropriate in high risk cases
CBCT
Coronectomy?
Controversial Pros and cons Medico-legal issue Should document discussed with pt if high risk of IAN damage Pt choice
