EWJ August 62 2025 web - Journal - Page 116
Wisdom Tooth Surgery Trigeminal
Nerve Complications part 2
by Dr R Kumar BDS LDS RCS MSc ImpDent MAGDS RCSEd PGCert Orthodontics
PGCert Facial Aesthetics, Examiner for the Royal College of Surgeons Edinburgh
Part two of a two part article
The radiographic presentation on a panoral
radiograph can show the IAN canal superimposing
over the roots, and in most cases the canal is visible on
radiographs.
Terminology
M3M terminal mandibular molar
LN Lingual nerve
IAN Inferior Alveolar nerve
IAC Inferior Alveolar canal
IAC
The IAC can sit away from the M3M, in close vicinity
or within the roots of the tooth (Iwanaga).
Introduction
Wisdom teeth are also known as terminal molars, 3rd
molars or 8s. They usually erupt between the ages of
17 and 24 years of age but in about 25% of worldwide
cases the teeth become impacted against the second
molars or the 7s (WHO).
The LN and M3M
Impacted mandibular molars (M3M) tend to suffer
future problems such as decay, soft tissue infection and
inflammation and commonly cause secondary decay
against the 7s.
The instance of decay on the 7s can range from 24 to
80% depending on the age of the patient (Fisher),
which can lead to gross destruction of the 7s, the need
for root canal treatment or even the removal of the
tooth.
Wisdom tooth impaction occurs as the wisdom tooth
is developing (and the roots are growing) but the
angulation prevents a full eruption.
The Lingual nerve can enter the oral cavity behind
the M3M over the bone crest (Tojyo) but commonly it
is further forward and below the alveolar crest. The
LN sits in the lingual mucosa but cannot be seen
radiographically as it is not housed within a canal.
Impaction generally means that the wisdom tooth is
stuck either horizontally, vertically or at an angle
against the 7 or the body of the mandible behind the
wisdom tooth.
M3M extractions and radiographs
When a surgical procedure is planned for the removal
of a M3M, the common radiograph taken is a panoral
or OPG. This is a 2-dimensional image with some
distortion.
The IAC and M3M
It is recommended that when the root apices are in a
close relationship with the IAN that a CT scan is taken
to ascertain the relationship (RCS).
M3M extractions and Lingual nerve damage
EXPERT WITNESS JOURNAL
114
AUGUST/SEPT 2025
