EWJ June 61 2025 web - Flipbook - Page 35
Third molar surgery
Due to the impaction, the wisdom tooth generally
flares up on a regular basis at least once or twice a year
and eventually the soft tissue infection is so severe that
the patient requests the removal of the impacted
tooth.
Mandibular nerve anatomy
A study carried out had reported follow up data on
Finnish students confirming that by the age of 38
years most impacted mandibular molars required removal (Venta).
However, there is increasing evidence that mandibular 8s should be removed before permanent symptoms or additional damage to the 7s occurs (Huang)
3rd molar surgery is one of the most common surgical procedures performed in secondary care in the
National Health Service (McCardle).
The Trigeminal nerve constitutes the largest sensory
cortex representation in the brain compared with
other sensory nerves, this is because the Trigeminal
nerve provides sensory innovation to sight, smell,
taste, hearing and speech.
M3M surgery is usually carried out in a surgical setting
such as a dental practice or an Oral Surgery Hospital
setting. The surgeon is usually a dentist with experience in oral surgery tooth extractions or an Oral
Surgeon.
Damage to the branches of the Trigeminal nerve during molar surgery can cause significant psychological
morbidity (Caissie).
M3M general post-surgery risks
During the surgical removal of the 8, a surgical flap is
usually raised, cortical bone is removed and the tooth
is then elevated completely.
The Trigeminal nerve (V) branches into the
Ophthalmic, Maxillary and Mandibular nerves.
The Mandibular nerve is the only branch that
contains motor fibres and innervates:
Anterior Division
Motor Innervation - Muscles of mastication
Sensory innervation - Buccal nerve (buccal mucosa)
Posterior Division
Auriculotemporal - sensory nerve to skin and area
around the TMJ and ear.
The flap is then closed and sutured and the patient is
usually given analgesics and on occasion antibiotics.
Patients at risk of postoperative infection can include:
• smokers
• patients with poor oral hygiene
• diabetics
• patients on immunosuppressants
• patients on bisphosphonate drugs
Lingual nerve (LN) - sensory nerve runs in the mucosa below and behind the M3M and the tongue side
mucosa
There is little evidence that patients who are
prescribed antibiotics after surgery have a reduced risk
of complications (Renton).
The more serious risk is damage to the mandibular
nerve branches during surgery.
Nerve damage could result in :
• Paraesthesia (the sensation of tingling, burning,
pricking or prickling, skincrawling, itching, “pins and
needles” or numbness on or just underneath your
skin)
• Anaesthesia
• Dysesthesia (unusual touch-based symptoms)
• Hyperesthesia
• Ageusia (loss of taste)
• Dysgeusia (altered taste)
• supplying the anterior 2/3rds of the tongue
• floor of the mouth
• lingual mucosa and gingivae
• submandibular and sublingual glands
• carries the Chorda Tympani nerve carrying taste
sensation to the anterior 2/3rds of the tongue
Nerve injury may be temporary and or subside after
6 months, however if longer the injury was considered
permanent (Iwanaga).
It is good practice that patients are warned of these
risks if they apply; see later.
EXPERT WITNESS JOURNAL
Inferior Alveolar nerve enters the mandible body at
the ramus and sits within the inferior alveolar canal
along with the Inferior Alveolar artery (IAA)
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JUNE 2025
