Three cranial nerves are at risk during
removal of the submandibular gland:
1 the marginal mandibular branch of the facial nerve
2 the lingual nerve
3 the hypoglossal nerve.
4-Wound closure
Haemostasis is confirmed and a vacuum suction drain
inserted.
. The drain remains for 24 hours.
Complications of submandibular gland excision
Complications are:
• haematoma
• wound infection
• marginal mandibular nerve injury
• lingual nerve injury
• hypoglossal nerve injury
• transection of the nerve to the mylohyoid muscle
producing
submental skin anaesthesia.
Tumours of the submandibular gland
Tumours of the submandibular gland are uncommon and
usually present as a slow-growing, painless swelling
within the submandibular triangle.
Only 50 per cent of submandibular gland tumours are
benign, in contrast to 80–90 per cent of parotid gland
tumours . In many circumstances, the swelling cannot, on
clinical
examination,
be
differentiated
from
submandibular
lymphadenopathy.
Most
salivary
neoplasms,
even
malignant
tumours,
are
often
slow
growing, painless swellings. Unfortunately, pain is not a
reliable indication of malignancy as benign tumours often
present with pain in the affected gland. presumably due to
capsular distension or outflow obstruction.
Salivary gland tumours incidence
Type
Location
Frequency
ignant (%)
Major Parotid Common 10–20
Submandibular Uncommon 50
Sublingual Very rare 85
Minor Upper aerodigestive tract Rare 90
Clinical features of malignant salivary tumours
These include:
• facial nerve weakness
• rapid enlargement of the swelling
• induration and/or ulceration of the overlying skin
• cervical node enlargement
Investigation
1-Computed tomography (CT) and MRI scanning are the
most helpful techniques for imaging tumours arising in
the major salivary glands.
*The tumour is intrinsic to the gland,
*whether it is circumscribed and probably benign or
diffuse, invasive and probably malignant.
*the relationship of the tumour to other anatomical
structures, which is helpful in planning surgery.
2-Open surgical biopsy is contraindicated as this may
seed the tumour into surrounding tissues, making it
impossible to eradicate microscopic deposits of tumour
cells.
3-Fine-needle aspiration biopsy is a safe alternative to
open biopsy.
There is evidence to suggest that, provided the needle
gauge does not exceed 18G, there is no risk of seeding
viable tumour cells. The role of fine-needle aspiration
biopsy is, however, controversial as it rarely alters
surgical management.
Management of submandibular gland tumours
As with all salivary gland tumours, surgical excision with
a cuff of normal tissue is the goal.
When the tumour is small and entirely encased within the
submandibular
gland
parenchyma,
straight
forward
intracapsular
submandibular
gland
excision
is
appropriate.
However, benign tumours that are large and project
beyond the submandibular gland are best served by
suprahyoid
neck
dissection,
preserving
the
marginal
mandibular branch of the facial nerve, lingual nerve and
hypoglossal nerves
THE PAROTID GLAND
Anatomy
The parotid gland lies in a recess bounded by the ramus of
the mandible, the base of the skull and the mastoid
process. It lies on the carotid sheath and the XIth and
XIIth cranial nerves and extends forward over the
masseter muscle.
The gland is enclosed in a sheath of dense deep cervical
fascia. Its upper pole extends just below the zygoma and
its lower pole into the neck. Several important structures
run through the parotid gland.
These include:
• branches of the facial nerve;
• the terminal branch of the external carotid artery that
divides into the maxillary artery and the superficial
temporal artery;
•
the retromandibular vein;
*
intraparotid lymph nodes.
The gland is divided into deep and superficial lobes,
separated by the facial nerve. Eighty per cent of the
parotid gland lies superficial and 20 per cent deep to the
nerve. An accessory lobe is occasionally present lying
anterior to the superficial lobe on the masseter muscle.
Developmental disorders
Developmental disorders such as agenesis, duct atresia
and congenital fistula are extremely rare.
Inflammatory disorders
Viral infections
Mumps is the most common cause of acute painful
parotid swelling and predominantly affects children. It is
spread via airborne droplets of infected saliva. The
disease starts with a prodromal period of 1–2 days, during
which the patient experiences fever, nausea and headache.
This is followed by pain and swelling in one or both
parotid glands. Parotid pain can be very severe and
exacerbated by eating and drinking. Symptoms resolve
within 5–10 days.
The
diagnosis
is
based
on
history
and
clinical
examination; a recent contact with an infected patient
with a painful parotid swelling is often sufficient to lead
to a diagnosis.
Atypical viral parotitis does occur and may present with
predominantly unilateral swelling or even submandibular
involvement. A single episode of infection confers life
long immunity.
Treatment
of
mumps
is
symptomatic
with
regular
paracetamol and adequate oral fluid intake.
Complications of mumps;
orchitis,
oophoritis,
pancreatitis,
sensorineural
deafness
and meningoencephalitis are rare, but are more likely to
occur in adults. Other viral agents that produce parotitis
include Coxsackie A and B, parainfluenza 1 and 3, .
Bacterial infections
Acute
ascending
bacterial
sialadenitis
is
historically
described in dehydrated elderly patients following major
surgery. Reduced salivary flow secondary to dehydration
results in ascending infection via the parotid duct into the
parotid parenchyma. Acute bacterial parotitis is now more
common
with
no
obvious
precipitating
factors.
The
patient presents with a tender, painful parotid swelling
that arises over several hours .
There is generalised malaise, pyrexia and occasional
cervical lymphadenopathy. The pain is exacerbated by
eating or drinking. The parotid swelling may be diffuse,
but often localises to the lower pole of the gland. Intraoral
examination may reveal pus exuding from the parotid
gland
papilla.
The
infecting
organism
is
usually
Staphylococcus aureus or Streptococcus viridans, .
treatment is with appropriate intravenous antibiotics. If
the gland becomes fluctuant, ultrasound may identify
abscess formation within the gland that may require
aspiration with a large bore needle or formal drainage
under general anesthesia. In the latter procedure, the skin
incision should be made low to avoid damage to the lower
branch of the facial nerve. Blunt dissection using sinus
forceps is preferred, and the cavity is opened to facilitate
drainage. A drain is inserted and left in situ for 24–72
hours.
Sialography
is
contraindicated
during
acute
infection.
Chronic bacterial sialadenitis is rare in the parotid gland
Recurrent parotitis of childhood;
Recurrent parotitis of childhood is a distinct clinical entity
of unknown aetiology and variable prognosis. It is
characterised by rapid swelling of one or both parotid
glands, in which the symptoms are made worse by
chewing and eating. Systemic upset with fever and
malaise is variable. The symptoms usually last from 3 to 7
days, and are then followed by a quiescent period of
weeks
to
several
months.
Children
usually
present
between the ages of three and six years, although
symptoms have been reported in infants as young as four
months. The diagnosis is based on the characteristic
history and can be confirmed by sialography. This shows
a
characteristic
punctate
sialectasis
likened
to
a
‘snowstorm’ .The condition usually responds to short
courses of antibiotics although, if recurrence is frequent,
prophylactic low-dose antibiotics may be required for
several months or even years. Few children require formal
parotidectomy. However, if the onset of symptoms is late,
e.g. adolescence/early adulthood, fewer patients respond
to
conservative
measures
and
may
require
total
conservative pradectomy
Human immunodeficiency virus-associated sialadenitis
Chronic parotitis in children is pathognomonic of human
immunodeficiency
virus
(HIV)
infection.
The
presentation of HIV-associated sialadenitis is very similar
to classical Sjögren’s syndrome in adulthood. Although
HIV-associated sialadenitis and Sjögren’s syndrome are
histologically similar, the former condition is usually
associated with a negative autoantibody screen. Other
presentations of salivary gland disease in HIVpositive
patients include multiple parotid cysts, which cause gross
parotid swelling and facial disfigurement.
CT
and
MRI
demonstrate the characteristic ‘Swiss
cheese’ appearance of multiple large cystic lesions . The
swollen glands are usually painless and may regress on
the institution of antiviral therapy.
Parotidectomy, however, may be indicated to improve
the appearance.
Obstructive parotitis
There are several causes of obstructive parotitis, which
produces intermittent painful swelling of the parotid
gland, particularly at mealtimes.
Papillary obstruction
Obstructive parotitis is less common than obstructive
submandibular
sialadenitis
but,
nevertheless,
can
be
caused by trauma to the parotid papilla through either an
over extended upper denture flange or a fractured upper
molar tooth. The subsequent inflammation and oedema
obstructs salivary flow, particularly at mealtimes. The
patient usually experiences rapid onset pain and swelling
at mealtimes. If left untreated, progressive scarring and
fibrosis in and around the parotid duct papilla will
produce a permanent stenosis.
Symptoms are unlikely to resolve unless a papillotomy is
performed. This is a simple procedure performed under
either local or general anaesthesia. The parotid duct is
cannulated, and the distal parotid duct is laid open by
incising longitudinally down onto the probe allowing free
drainage of Saliva
Stone formation
Sialolithiasis is
1- less common in the parotid gland (20 per cent) than in
the submandibular gland (80 per cent).
2-Parotid duct stones are usually radiolucent and rarely
visible on plain radiography.
They are frequently located at the confluence of the
collecting ducts or located in the distal aspect of the
parotid duct adjacent to the parotid papilla. Parotid gland
sialography is usually required to identify the stone. A
stone located in the collecting duct or within the gland
may
be
managed
by
either
endoscopic
retrieval,
lithotripsy or, least likely, surgical removal
via a parotidectomy approach.
Tumours of the parotid gland