parotid gland, intro. ,def., classificatn,anaomy, dev. histology, dd, function,referances,

1. PAROTID GLANDS
 PRESENTED BY-
 PARTHSARTHI GAUTAM
 1ST YEAR M.D.S
 DEPT. OF ORAL MEDICINE & RADIOLOGY
 NARSINHBHAI PATEL DENTAL COLLEGE & HOSPITAL

2. content
 introduction
 Definition
 Development
 Anatomy
 Parts & relations
 Blood supply, nerve supply
 Histology
 Applied anatomy
 Differential diagnosis
 References
No. of slides- 41

3. The salivary glands in mammals are exocrine glands, glands
with ducts, that produce saliva. They also secrete amylase,
an enzyme that breaks down starch into maltose
 Parotid gland
 Submandibular gland
 Sublingual gland
 Minor salivary glands

4. PAROTID GLANDS
PAIRED PAROTID GLANDS ARE LARGEST OF SALIVARY
GLANDS LYING LARGELY BELOW THE EXTERNAL ACOUSTIC
MEATUS BETWEEN MANDIBLE AND
STERNOCLEIDOMASTOID MUSCLE AND IT ALSO PROJECTS
FORWARDS ON THE SURFACE OF MASSETER

5.  Occupies the deep hollow behind the
ramus of the mandible
 Wedge-shaped when viewed externally ,
with the base above & the apex behind
the angle of the mandible

6. Gross anatomy.
 Weight– 25g.
 Shape – Inverted pyramid.
In 30% cases upper and
lower poles are rounded.
 Surface – Irregular, lobulated.

7.  Site – in the parotid region bounded by
anterior – posterior border of body of ramus.
posterior – mastoid process and
sternocleidomastoid muscle.
inferior – digastric and stylohyoid.
superior – external acoustic meatus and TMJ.
Medially – Styloid process.
 Coverings –
- Inner true capsule formed by condensation of fibrous stroma of the gland.
- Outer false capsule[Parotid Sheath] formed by splitting of investing layer of
deep cervical fascia.

8. DEVELOPMENT
 Each parotid is developed during 4th week in intrauterine
life from angle of primary oral fissure as an ectodermal
furrow.
 The groove is converted into tube which forms duct and
opens into angle of primitive mouth.
 From the lateral end of duct cords of ectodermal cells
project into surrounding mesoderm and subsequently
canalise.

9. The salivary glands arise as buds
from
The epithelial lining of the mouth;
the
parotid appears during the fourth
week
In the angle between the maxillary
process and the mandibular arch
Opening of parotid duct indicates
position of angle of primitive mouth

10. Stomodeum
Buccopharyngeal
membrane
Fore-gut
Mid-gut
Hind-gut
Proctodeum
Cloacal
membrane
Pre-Laryngeal
(Cephalic part)
Post-Laryngeal
(Caudal part)
GUT TUBE
Pharynx and
Part of definitive
Mouth cavity
Skin ectoderm
Ectodermal
furrow
Parotid gland
4th week of IUL

11. With the growth of maxillary and mandibular process the duct opening is
shifted to vestibule opposite the upper 2nd molar tooth.
 Ectodermal origin is proved by the presence of myoepithelial cells.
 During development the gland lies in between the branches of facial nerve,
as development progresses it envelopes the branches.
 The parotid development is usually associated with the transient ectodermal
outgrowth known as Chievitz’s organ. This structure may contribute to the
parotid gland but usually disappears.

12. APEX BASE
UPPER SURFACE
SURFACES BORDERS
SUPERFICIAL/
LATERAL
ANTERO- MEDIAL POSTERO-MEDIAL
ANTERIOR POSTERIOR MEDIAL
Parts

13. Parotid – 3 sided pyramid
Medial border
Apex
Superior
surface
(Base)
Superficial
Anterior border surface
Posterior border

14. Parts & relation
 BASE – UPPER PART OF THE GLAND
RELATION
EXTERNAL ACOUSTIC MEATUS,
TEMPOROMANDIBULAR JOINT
,SUPERFICIAL TEMPORAL VESSELS,
AURICULOTEMPORAL NERVE,
TEMPORAL BRANCH OF FACIAL NERVE

15. APEX
 DIRECTED DOWNWARDS –
 SMALL PART LIES IN CAROTID TRIANGLE
RELATION
ANTERIOR & POSTERIOR DIVISION OF
RETROMANDIBULAR VEIN,CERVICAL BRANCH OF
FACIAL NERVE

16.  Superficial (lateral)
 Skin & superficial fascia
 Great auricular nerve
 Parotid lymph nodes

17.  Anteromedial:
1.Stylomandibular ligament
2.Medial pterygoid
3.Posterior border of the ramus
of mandible
4.Massater
5.Terminal branches of the
facial nerve
1
2
3
4
5

18.  Posteromedial:
 Carotid sheath with its contents
 Styloid process & attached
muscles
 Facial nerve
 Posterior belly of digastric muscle
 Mastoid process
 Sternocleidomastoid
1
2
3
4
5
6

19. ANTERIOR BORDER
ZYGOMATIC BRANCH OF FACIAL NERVE,
TRANSVERSE FACIAL VESSELS,
UPPER BUCCAL BRANCH OF FACIAL NERVE,
ACCESSORY PAROTID DUCT,
PAROTID DUCT,
LOWER BUCCAL BRANCH OF FACIAL NERVE,
MARGINAL MANDIBULAR BRANCH OF FACIAL
NERVE

20.  POSTERIOR BORDER
STERNOCLEIDOMASTOID MUSCLE,
POSTERIOR AURICULAR VESSELS
MEDIAL BORDER
PHARYNX

21. Processes
The gland is an irregular lobulated mass, sends ‘processes’ in
various directions. These include:
 Glenoid process, that extends upward behind
the temporo-mandibular joint, in front of
external auditory meatus
 Facial process, that extends anteriorly onto the
masseter muscle
 Accessory process (part), small part of facial
process lying along the parotid duct
 Pterygoid process, that extends forward from
the deeper part, lies between the medial
pterygoid muscle & the ramus of mandible
 Carotid process, that lies posterior to the
external carotid artery

22. Structures Coursing Within the Parotid Gland
1.Auriculotemporal nerve
2.External carotid artery
3.Retromandibular vein
4.Facial nerve
A few lymph nodes are
scattered in the
substance of the gland
Deep
Superficial
1
2
3
4

23. Lobes
 The facial nerve
courses horizontally
through the gland
and divides it into:
 Superficial lobe
 Deep lobe
Superficial lobe
Deep lobe
Facial nerve

24. PAROTID DUCT
 KNOWN AS STENSEN’S DUCT
 LENGTH – 5CM
 CARRIES SALIVA TO THE ORAL CAVITY
COURSE
 FORMS BY THE UNION OF SMALLER DUCT FROM THE GLAND, RUNS ON
THE MASSETER MUSCLE & BENDS AT THE ANTERIOR BORDER OF THE
MUSCLE & PIERCES SUCCESSIVELY BUCCAL PAD OF FAT,
BUCCOPHARYNGEAL FASCIA & BUCCINATOR MUSCLE. AGAIN BENDS
& FINALLY EMERGES INSIDE THE ORAL CAVITY AT THE CROWN OF THE
UPPER 2ND MOLAR TOOTH

25.  Arterial supply:
 External carotid artery & its terminal
branches
 Venous drainage:
 Into the retro-mandibular vein
 Lymph Drainage:
 Into the parotid & then into the deep
cervical lymph nodes

26. Nerve Supply
 Sensory :
 Auriculotemporal n.
 Autonomic:
• Sympathetic through plexus
around the arteries
( around ECA)
• Parasympthetic through otic
ganglion (CN9-tympanic n.-
lesser petrosal n.- otic
ganglion-auriculotemporal
n.)

27. Histology
Salivary glands are composed of serous and
mucous acini, the proportions of which determine
the type of salivary secretion from each
Duct
Parotid is mainly serous
Sublingual is mainly mucous
Submandibular is mixed

28. The Secretory Unit
– Acinus (serous,
mucous, mixed)
– Myoepithelial cells
– Intercalated duct
– Striated duct
– Excretory duct

29. Striated & Intercalated ducts well developed
in serous, NOT mucous glands
Striated duct: HCO3 into, Cl from lumen
Intercalated duct: K into lumen, Na from
lumen, producing hypotonic fluid
Excretory ducts do NOT modify saliva

30.  Minor salivary glands tend to be under local control, whereas
major glands are parasympathetically controlled
 Saliva is hypotonic, with low concentrations of NaCl, high
KHCO3
Antibodies (IgA), amylase, lysozyme, Lactoperoxidase
Submandibular saliva has relatively high Ca

31. Functions
Main function is lubrication and cleansing oral cavity
Initiation of starch digestion
Immunological
HCO3 retards growth of acidophilic bacteria
Maintenance of dentition (Ca, Po4, Mg)
Normal outflow is 1-2L/day
parotid gland is the largest, provides only 25% of the total
salivary volume

32. Salivary hypofunction
– Candidiasis
– Lichen Planus
– Burning Mouth
– Aphthous ulcers
– Dental caries
– Xerostomia not reliable

33. Effects of Aging
• Total salivary flow independent of age
• Acinar cells degenerate with age
• Submandibular gland more sensitive to
metabolic/physiologic change
• Unstimulated salivary flow more greatly
affected by physiologic changes

34. Diseases of parotid gland
Congenital
Aplasia or atresia
Acquired
Infective
Mumps
Bacterial sialadentitis
Autoimmune
Sjögren's syndrome

35. Inflammatory
sialadenitis
Neurological
Frey's syndrome
Neoplastic
Salivary gland neoplasm
Idiopathic
Sialolithiasis
Sialadenosis

36. Applied aspect
Acute bacterial parotitis
 most often caused by a bacterial infection of Staphylococcus
aureus but may be caused by any commensal bacteria.
It often occurs in the setting of debilitation, dehydration,
and poor oral hygiene, particularly among elderly
postoperative patient

37. Mumps
 is a viral disease of the human species, caused by the mumps virus
Paramyxovirus
 transmitted by direct contact, droplet spread, or contaminated
objects
 Painful swelling of the parotid gland
 Fever and headache are prodromal symptoms of mumps, together
with malaise and anorexia. Other symptoms of mumps can include
dry mouth, sore face and/or ears and occasionally in more serious
cases, loss of voice.

38. Sjögren's syndrome
 : Chronic inflammation of the salivary glands may also be an
autoimmune disease known as Sjögren's syndrome
 The disease most commonly appears in people aged 40–60 years,
but it may affect small children.
 women versus men is approximately 9:1.
 The involved parotid gland is enlarged and tender at times.
 The cause is unknown. The syndrome is often characterized by
excessive dryness in the eyes, mouth, nose, vagina, and skin

39. Sialolithiasis
a condition where a calcified mass forms within a salivary gland
•Pus discharging from the duct (infection).
•Cervical lymphadenitis
•Pain, which is intermittent, and may suddenly get worse before mealtimes
•, and then slowly get better.
•Swelling of the gland, also usually intermittent,
•Tenderness of the involved gland
•Erythema

40.  Also known as gustatory sweating or
auriculo-temporal nerve syndrome
 Commonly occurs after parotid surgery
or trauma
 It reflects the aberrant innervation of
sweat glands on the face by regrowing
parasympathetic secretomotor axons
that would have previously innervated the
parotid gland
 It is characterized by
o Sweating
o Warmth
o Redness of the face
as a result of salivary stimulation by the smell
or taste of food

41. Salivary Gland Tumors
 pleomorphic adenomas
originate from the intercalated
duct cells and
myoepithelial cells
 oncocytic tumors originate
from the striated duct cells
 acinous cell tumors originate
from the acinar cells,
 Mucoepidermoid tumors
and squamous cell
carcinomas develop in the
excretory duct cells.

42. Differential Diagnosis of Parotid
Gland Enlargement
 Lymphoma
 Actinomycoses
 Cat-scratch disease
 Sjogren’s syndrome
 Viral infection

43. Referances
 Grays human anatomy, 14th edition: Elsevier publications
 B.d churasia’ human anatomyvol:3
 Shafers text book of oral pathology & microbiology, 6th edition
 Davidson’s text book of general medicine 18th edition

44. Thanking you
 Guided by-
 Dr. Basavaraj kallalli ( dean & HOD)
 Dr. kamala.R.
 Dr. swaroop
 Dr. shurthi