EWJ August 62 2025 web - Journal - Page 117
During a surgical procedure for removal of the M3M,
the surgeon will normally raise a soft tissue flap
buccally and lingually to the M3M.
• partial horizontal sectioning and levering the crown
(lower risk of lingual plate damage)
• crown elevate buccally
This is to gain exposure and a better perspective of
the impacted molar.
However on raising a lingual flap the surgeon may
either make an incision to release the flap thereby
being at risk of severing the lingual nerve or may use
a lingual flap retractor but the pressure of the retractor may also cause compression or damage to the
lingual nerve (Renton).
Where the M3M is impacted distally, the surgeon may
create a larger flap and remove cortical bone behind
the tooth. This runs the risk of damage to the LN in
cases of an abnormal nerve pathway (Tojyo). The incidence of LN injury is up to 2% of M3M extractions
(Tojyo).
Bonantha
M3M extractions and IAN damage
There is a heightened risk of neurosensory damage
when the canal shows radiographic narrowing, direct
contact with the roots, a lingual course with or without
cortical plate perforation and an intraroot course of
the canal (RCS).
Renton
The advantages are :
• minimal risk to the nerves
• smaller surgical field
• less trauma to the mandible
• faster surgical procedure (30mins)
• faster healing
• resolution of pericoronitis
• less bone resorption distal to the 7
Ct scan images of root/IAC relationships
The IAN can become damaged, severed or
compressed whilst the roots are elevated (Iwanaga).
The reported incidence rate of injury ranges from
0.35 to19% when the roots are close to the IAN
(Iwanaga).
Disadvantages :
• if roots are loosened, they may migrate upwards
(Renton)
Is there a way to minimise risks to the nerves?
If an impacted M3M needs removal, then a surgeon
has 2 options:
• remove the whole tooth and the risk nerve damage
• remove the crown and leave the roots in situ,
coronectomy
• if the roots are loosened then they may need to be
removed at the same time, risking damage to the IAN
• if the nerve pulp is left behind and become necrotic,
it may become infected
For a surgeon to reduce the risks of nerve damage it
has been suggested that one should avoid (Renton) :
• raising a lingual flap
• removing bone distally to the M3M
• applying pressure on the IAN during elevation
• applying a pulling force on the IAN during
elevation
• trying to remove the roots
• a second surgical procedure may be required at a
much later date
Legal issues Winterbotham versus Sharak (N Moody
KC)
This case was heard between 16-19 July 2024 and
involved Lingual nerve damage to Mrs Winterbotham
during the elevation of a disto-angular impacted LR8
by Mr Sharak, a specialist oral surgeon.
Coronectomy is such a technique
Coronectomy or partial odontectomy involves :
• buccal mucoperiosteal flap
• buccal bone removal
• crown sectioned horizontally or vertically at the root
level
EXPERT WITNESS JOURNAL
It was argued that the risks of LN injury were not
explained to the claimant. The claimant was not
o]ered a coronectomy procedure. Mr Sharak did not
undertake coronectomies.
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AUGUST/SEPT 2025
