The surgical anatomy of major salivary glands has many significant applications in maxillofacial surgery. Understanding these important anatomic relations- variations enables surgeons to perform the surgical procedures safely. Knowledge of these concepts helps us to recognize the problems and complications as and when they occur and manage them accordingly.

1. GOOD MORNING

2. SURGICAL ANATOMY OF MAJOR SALIVARY GLANDS
(DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY)
GUIDED BY:
Dr. D S Gupta
(Professor)
04-12-2018
(Tuesday)
PRESENTED BY:
Dr. Samarth Johari
P.G 1st Year

3. CONTENTS
 Introduction
 Development of Salivary Glands
 Parotid Gland
 Submandibular Gland
 Sublingual Gland
 Evaluation of Salivary Glands
 Conclusion
 References

4. INTRODUCTION
 Exocrine Glands that open or secrete into oral cavity
 Major function secretes saliva
 Saliva fluid which has partly chemical & partly physical functions
its enzymes initiates 1st phase of
digestion & has antibacterial
action related to dental caries
moistens & lubricates food

5.  Anatomically, divided into 2 groups :
i. Major salivary glands
• Larger in size
• Situated farther from inner lining of oral cavity & open with strong, wide
ducts
• Includes paired –
a) Parotid
b) Submandibular
c) sublingual glands
ii. Minor salivary glands
• Smaller in size
• Situated in the mucous layer & open with numerous narrow ducts on
mucous membrane
• Divided according to their site -
a) Palatine b) Lingual c) Incisive
d) Labial e) Buccal

6.  According to their secretion, divided as –
i. Serous (albuminous) :
• Consists of serous acini
• Responsible for serous secretion that contains ptyalin (
ᵅ-amylase) which
is responsible for digestion of starches
ii. Mucous :
• Consists of mucous acini
• Responsible for mucous secretion that contains mucin for lubrication &
surface protecting purposes
iii. Mixed :
• Consists of both serous & mucous acini

7. DEVELOPMENT OF
SALIVARY GLANDS
 Originate from oral epithelial buds
invading underlying
ectomesenchyme
 Origin of epithelial buds –
i. Ectodermal in parotid &
minor salivary glands
ii. Endodermal in
submandibular & sublingual
glands
 Connective tissue stroma & blood
vessels originate from
mesenchyme

9.  Major salivary glands develop in 6 main
stages :
i. Bud formation via introduction of oral
epithelium by underlying mesenchyme
ii. Formation & growth of epithelial cord
iii. Initiation of branching in terminal
parts of epithelial cord & continuation
of glandular differentiation
iv. Dichromatous branching of epithelial
cord & lobule formation
v. Canalization of presumptive ducts
vi. Cytodifferentiation

10. PAROTID GLAND
 Largest & weighs on an average – 15-30gm
 Bulk of gland situated in retromandibular
fossa
 Lies in shallow triangular shaped trench
formed by :
i. Posteriorly - Sternocleidomastoid muscle
ii. Anteriorly – ramus of mandible
iii. Superiorly (base of trench) – external
acoustic meatus (situated in groove of
gland) & posterior aspect of zygomatic
arch
 Extends anteriorly over masseter & inferiorly over posterior belly of digastric
muscle

11.  In most persons, gland is divided into 2 lobes :
i. Superficial lobe – comprises of bulk of gland
ii. Deep lobe
 2 lobes are connected by narrow isthmus
mostly found in bifurcation of facial nerve into upper temporal & lower cervical
division
 Branches of facial nerve lies b/w these lobes for a short distance
 An accessory parotid gland (socia parotidis) may also be present lying
anteriorly over masseter muscle b/w parotid duct & zygoma
Is different from parotid tissue as it may contain both mucinar & serous acini & its
ducts empty directly into parotid duct through 1 tributary

12.  Fascia/Capsule of parotid gland :
• Capsule continuation of deep
cervical fascia & splits into superficial
& deep layers to enclose parotid
gland
Extends to stylomandibular ligament
which seperates superficial
& deep lobes of parotid gland
Is thick & extends superiorly from
masseter & sternocleidomastoid to
zygomatic arch
• Is dense & inelastic because it covers
masseter deeply (parotid masseteric
fascia)
 Parotid swellings are very
painful

13.  Stensen’s Duct :
• Aka ductus parotideus
• Secretes serous saliva
into vestibule
• From anterior border of
gland runs parallel to
zygoma (approx. 1cm
below it) in anterior
direction across
masseter muscle
Then turns sharply to
pierce buccinators muscle
to enter oral cavity opposite
to maxillary 2nd molar
Parotid Duct Injury
 may be damaged in injuries to the face
 may be inadvertently cut during surgical
operations on the face

14.  Neural Anatomy :
• Facial nerve exits skull from
stylomastoid foramen & its main trunk,
in parotid gland (at pes anserinus :
goose foot), divides into upper
temporofacial & lower cervicofacial
divisions approx. 1.3 cm from
stylomastoid foramen
• Upper temporofacial division –
forms of temporal, zygomatic & buccal
branches
• Lower cervicofacial division – forms
marginal mandibular & cervical
branches
 Facial nerve courses through the gland without supplying any structure in it

15.  Nerve Supply :
• Parasympathetic –
secretomotor through
auriculotemporal nerve
• Sympathetic –
vasomotor through
external carotid plexus
from superior cervical
ganglion. Also supplies
sweat glands, cutaneous
blood supply
• Sensory – through
auriculotemporal nerve
 Parotid fascia is innervated by sensory fibers of great auricular nerve (C2,
C3)

16. Frey’s Syndrome
 Aka “gustatory sweating”
 Seen after parotidectomy
 Acetylcholine acts as
neurotransmitter for both
postganglionic sympathetic &
parasympathetic fibers & there may
be re-innervation of sweat glands by
regeneration of parasympathetic
fibers from residual parotid gland
Patients develop sweating & flushing of
skin overlying parotid region while
chewing
Minimizing Risk Of Frey’s
Syndrome
 Complete & meticulous
superficial paroidectomy
 Developing skin flaps of
appropriate thickness over
exposed apocrine glands of skin

17.  Arterial Supply :
• From branches of external carotid
artery (superficial temporal artery,
maxillary artery & transverse facial
artery)
 Venous Drainage :
• Maxillary vein + superficial temporal vein
Retromandibular vein
Anterior branch Posterior branch
Unites with
posterior facial
vein to form
common facial
vein
Unites with
posterior
auricular vein to
drain into external
jugular vein

18.  Lymphatic Drainage :
• Only salivary gland with 2 nodal layers, both of which drain into superficial &
deep cervical lymph systems
• 90% nodes are in superficial layer b/w gland & its capsule
i. Superficial Nodes – drain parotid gland, external auditory canal, pinna,
scalp, eyelids & lacrimal glands
ii. Deep Nodes – drain gland, external auditory canal, middle ear,
nasopharynx & soft palate

19. Parotid Infection
 Parotid abscess may be caused by
spread of infection from oral cavity
 Parotid lymph node draining an
infected area may also cause parotid
infection
 Parotitis/Mumps is an infection of
parotid gland caused by
paromyxovirus & causes severe pain
Drainage of Parotid Abscess
 Done on the basis of Hilton’s method of
incision & drainage
 Vertical incision in front of ear & then a
transverse incision to protect the branches of
facial nerve.

20.  Parapharyngeal Space :
• Tumors of deep parotid lobe extend
medially into PPS
• Just posterior to infratemporal fossa like
inverted pyramid in shape
• Boundaries :
i. Apex – greater cornu of hyoid bone
ii. Base – petrous bone of skull base
iii. Medial – lateral pharyngeal wall
(includes superior constrictor,
buccopharyngeal fascia, tensor veli
palatine)
iv. Lateral – ramus, medial pterygoid
v. Anterior – pterygoid fascia,
pterygomandibular raphae
vi. Posterior – carotid sheath,
prevertebral fascia

21.  Surgical Approach to Parotid Gland :
• Cervicomastoidfacial Incision –
 Given by Blair in 1912 &
modified by Bailey in 1941
 Modification is aka “lazy ‘s’
incision”
 Incision is given in relaxed
preauricular skin crease, curves
around lobule toward mastoid
tip & then anteriorly along
natural skin crease, curving
approx. 2 finger breadths below
angle of mandible

22. SUBMANDIBULAR GLAND
 Earlier was called “submaxillary gland”
 2nd largest major salivary gland & weighs 7-
16gm
 Located in submandibular triangle –
• Superior boundary formed by inferior
border of mandible
• Inferior boundaries formed by anterior
belly & posterior belly of digastric
 Other structures that lie in this triangle are
submandibular lymph nodes, facial artery &
vein, mylohyoid muscle & lingual, hypoglossal
& mylohyoid nerves

23.  Most part of submandibular
salivary gland lies posterolateral
to mylohyoid muscle
During neck dissection or
submandibular gland excision,
mylohyoid muscle must be gently
retracted to expose lingual nerve
& submandibular ganglion

24.  Fascia/Capsule of submandibular gland :
• Enclosed by middle layer of deep
cervical fascia
• Superficial layer is attached to base of
mandible
• Deep layer is attached to mylohyoid line
of mandible
 Marginal mandibular branch of facial nerve is superficial to this fascia,
therefore, care has to be taken while performing surgeries in
submandibular region
 Division of submandibular gland fascia (when oncologically appropriate)
is a reliable method of preserving & protecting marginal mandibular
branch of facial nerve during neck dissection & submandibular gland
resection

25.  Wharton’s Duct :
• Has both serous & mucous cells which
empty into submandibular duct via
ductules
• Exits anteriorly from sublingual aspect
of gland (deep to lingual nerve & medial
to sublingual gland)
• Forms Wharton’s duct (approx. 4-5 cm
long) b/w hyoglossus & mylohyoid on
genioglossus
• Empties lateral to lingual frenulum
through papilla in floor of mouth behind
lower incisor teeth

26.  Nerve Supply :
• Parasympathetic –
secretomotor from
superior salivatory
nucleus in pons passes
through nervus
intermedius & further
joins facial nerve
• Sympathetic –
vasomotor through
superior cervical ganglion
via lingual artery &
causes mucoid secretion
• Sensory – through
auriculotemporal nerve

27.  Arterial Supply :
• Main blood supply is by facial artery
& its branch submental artery
• Runs medial to posterior belly of
digastric
• Artery exits at superior border of
the gland & at the inferior border of
mandible (at facial notch)
• then runs adjacent to inferior
branches of facial nerve
 During submandibular gland resection, facial artery must be sacrificed
twice –
1st at inferior border of mandible
2nd just superior to posterior belly of digastric

28.  Venous Drainage :
• Mainly drained by anterior facial
vein
Anastomoses with infraorbital &
superior ophthalmic veins
• Over the middle aspect of the
gland, union of anterior facial vein
& posterior facial vein forms
common facial vein
exits submandibular triangle to join
internal jugular vein
 Since, anterior facial vein lies just deep to marginal mandibular division of
facial nerve, its ligation & superior retraction can help preserve marginal
mandibular nerve

29.  Lymphatic Drainage :
• Prevascular & postvascular lymph
nodes drain submandibular gland
• Not embedded in tissue but present
b/w gland & its fascia
• Lie in close approximation to facial
artery & vein at superior aspect of
gland
• Frequently associated with oral
cancers (specially in buccal mucosa
& floor of mouth)
 While ligating facial artery & its associated structures care must be taken
not only to resect all associated lymphoadipose tissue, but also to preserve
marginal mandibular nerve which runs close to it

30. Sialolithiasis is more common in
submandibular salivary glands because :
i. Saliva is more alkaline
ii. Higher concentration of calcim &
phosphate in saliva
iii. High mucous content
iv. Longer & curved duct
v. Flow against gravity
 Stone in duct can be palpated
bimanually in floor of mouth & can
even be seen if sufficiently large
 Diagnosis - presence of a tense
swelling below the body of the
mandible, which is greatest before or
during a meal and is reduced in size
or absent between meals

31. Enlargement of the Submandibular Lymph
Nodes & Swelling of the Submandibular
Salivary Gland
commonly enlarged as a result of a
pathologic condition of the scalp, face,
maxillary sinus, or oral cavity
One of the most common causes of painful
enlargement of these nodes is acute infection
of the teeth

32.  Surgical Approach to Submandibular
Gland :
• Incision placed 2-4 cm below the
lower border of mandible to
preserve the marginal mandibular
nerve (branch of facial nerve)

33. SUBLINGUAL GLAND
 Smallest salivary gland weighing 2-4gm
 Lies beneath the mucous membrane
(sublingual fold) of the floor of the
mouth, close to the frenulum of the
tongue
 Has both serous and mucous acini
 Several ducts : 5-15 in no. (of Rivinus)
from superior portion of gland either
secrete directly into floor of mouth or
empty in Bartholin’s Duct that continues
into Wharton’s Duct

34.  Nerve Supply :
• Parasympathetic –
secretomotor
preganglionic – facial
nerve via chorda tympani
& post-ganglionic – via
lingual nerve
• Sympathetic –
sympathetic nerves
innervating the gland
travel from cervical
ganglion with facial
artery

35.  Arterial Supply :
• Supplied by submental &
sublingual arteries
(branches of lingual & facial
arteries respectively)
 Venous Drainage :
• Corresponds to arteries
 Lymphatic Drainage :
• Drained by submandibular
lymph nodes
Structures at risk during dissection of gland
 Submandibular duct (lies superficially in the floor) & lingual nerve (travels
inferior to duct before entering the tongue)
 Sublingual artery & vein (lies medial to sublingual gland)

36. Ranulas
 Cysts or mucoceles of sublingual
salivary gland
 Can exists either simply within
sublingual space or plunging
posteriorly to mylohyoid muscle
into neck
 Simple ranula – appears as bluish
non-tender mass in floor of mouth
& may either be a retention cyst or
an extravasation pseudocyst
 Plunging ranula – appears as soft,
painless, cervical mass & is always
an extravasation pseudocyst

37. EVALUATION OF SALIVARY GLANDS
 Symptoms are non-specific
Pt. comes with complain of swelling, pain, xerostomia, foul taste & sometimes
sialorrhea (excessive salivation)
Enlargement of major or minor salivary glands, most commonly the parotid or
submandibular, may occur on one or both sides
Parotitis typically presents as preauricular swelling, butmay not be visible if deep
in the parotid tail or within the substance of the gland
Submandibular swelling presents just medial and inferior to the angle of the
mandible
Salivary gland swellings are single, larger & smoother than that of lymphatic origin

38.  Radiologic and Endoscopic
Examination of the Salivary Glands :
1. Sialography –
• relies on the injection of
contrast medium into glandular
ducts so that the pathway of
salivary flow can be visualized
by plain-film radiographs
• most common indication for
sialography is the presence of a
salivary calculus
• should not be performed when
the patient has an acute
salivary gland infection, has a
known sensitivity to iodine-
containing compounds

39. 2. Computed Tomography (CT) –
• Used to assess the parotid and
submandibular glands
• Advantage of CT imaging is the
two-dimensional view of the
salivary glands, which can
elucidate relationships to
adjacent vital structures as well
as to assess the draining
cervical lymphatics

40. 3. CT- sialography –
• Combination of CT & sialography for
difficult cases
4. Magnetic Resonance Imaging (MRI) –
• provides better contrast resolution,
exposes the patient to less harmful
radiation, and yields detailed images on
several different planes without patient
repositioning
• especially used in discriminating
between deep lobe parotid tumors
• inferior to CT scanning for the detection
of calcifications and early bone erosion
• chronic inflammation of the salivary
glands and calculi are not indications
for MRI

41. 5. Sialendoscopy –
• minimally invasive
technique that inspects
the salivary glands using
narrow-diameter, rigid
fiberoptic endoscopes
• lacrimal probes are used
to gently dilate the
ductal orifice and then
the endoscope is
introduced under direct
visualization
• in one setting, at the
time of diagnosis,
treatment and therapy
for benign lesions can be
performed

42. The surgical anatomy of major salivary glands has many
significant applications in maxillofacial surgery. Understanding
these important anatomic relations- variations enables surgeons
to perform the surgical procedures safely. Knowledge of these
concepts helps us to recognize the problems and complications as
and when they occur and manage them accordingly.
CONCLUSION

43.  Salivary Gland Disorders By Myers, Ferris – Springer
 Orban’s Oral Histology & Embryology
 Oral Anatomy by Sicher and DuBrul
 Clinical Anatomy By Regions – Richard S. Snell
 Gray’s Anatomy
 Oral & Maxillofacial Surgery by Fonseca
 Textbook of Human Anatomy by B.D.Chaurasia, Vol.3
 Textbook of Human Embryology by Inderbir Singh
REFERENCES