The document discusses the parotid gland. It covers the gland's location below the external ear, development from an ectodermal furrow, and capsule formed by the deep cervical fascia. It describes the gland's surfaces, borders, and relations to surrounding structures like the facial nerve and parotid duct. The parotid gland provides saliva through its secretory and excretory functions and is important for oral health. Surgical removal of the gland can increase risks of dental caries.
2. INTRODUCTION
DEVELOPMENT
PAROTID CAPSULE
EXTERNALFEATURES
RELATIONS
STRUCTUREWITHIN THE PAROTID GLAND
PAROTID DUCT
NERVE SUPPLY
LYMPHATIC DRAINAGEAND LYMPH NODES
FUNCTIONS OF PAROTID GLAND
ROLEOF PUBLIC HEALTH DENTIST
CONCLUSION
REFERENCES
3. The salivary glands in mammals are a group of
compound exocrine glands, glands with ducts, that
produce saliva.
They are:
Parotid gland
Sub mandibular gland
Sublingual gland
Minor salivaryglands
4. Paired parotid glands lying largely below the external acoustic
meatus between Mandible And Sternocleidomastoid
muscle and it also projects forwards on the surface of
Masseter.
5. On the surface of the masseter, small detached part lies
between zygomatic arch and parotid duct called as Accessory
parotid gland or‘socia parotidis’
It is irregular, wedge shaped, and unilobular.
Parotid is 14-28 grams in weight and provides 60- 65% of total
salivaryvolume.
Dimensions:- 5.8 cm ( craniocaudal dimension)
3.4 cm (ventraldorsal dimension).
6. The parotid salivary glands appear early in the 4th week of prenatal
development and are the first major salivary glands formed as an
ectodermal furrow.
The epithelial buds of these glands are located on the inner part of
the cheek, near the labial commissures of the primitive mouth.
These buds grow posteriorly toward the otic placodes of the ears and
branch to form solid cords with rounded terminal ends near the
developing facial nerve.
7. Later, at around 10 weeks of prenatal development, these cords
are canalized and form ducts, with the largest becoming the
parotid duct for the parotid gland.
The rounded terminal ends of the cords form the acini of the
glands.
Secretion by the parotid glands via the parotid duct begins at about
18 weeks of gestation. Again, the supporting connective tissue of
the gland develops from the surrounding mesenchyme
8.
9. The investing layer of the deep cervical fascia forms acapsule for the
gland. The fasica splits(between the angle of the mandible and the
mastoid process) to enclose the gland.
Consists of
Superficial layer – It is thick and adherent to gland. It extends from the
masseter and Sternocliedomastoid to the Zygoma.
Deep layer – It is thin and is attached to the styloid process, the mandible
and the tympanic plate.
10. The gland resembles a three sided pyramid. The apex of the pyramid
is directed downwards.
The gland has four surfaces:-
Superior (base of the pyramid)
Superficial
Anteromedial and
Posteromedial
The surfaces are separted by 3 borders:
a) Anterior b) Posterior and3) Medial
12. APEX
It overlaps the posterior belly of the
diagastric and the adjoining part of the
carotid triangle.
The cervical branch of the facial nerve
Two divisions of the retromandibular vein emerge through it.
13. SUPERIOR SURFACE OR BASE
forms the upper end of the gland ,Small And Concave.
The Cartilagious Part Of The External Acoustic Meatus.
The Posterior Surface Of The Temporo Mandibular Joint
The Superficial Temporal Vessels.
The Auriculotemporal nerve
14. SUPERFICIAL SURFACE
It is the largest of the four surfaces. It is covered with
Skin
Superficial fascia containing the anterior branches of great
auricular nerve, the perauricular or superficial parotid lymph
nodes and the posterior fibers of the platysma and risorius.
the parotid fascia which is thick and adherent to gland
a few deep parotid lymph nodes embedded in the gland
15.
16. ANTEROMEDIAL SURFACE:
It is grooved by posterior border of the ramus of the mandible. It is
related to
The Masseter
The lateral surface of temporomandibular joint
The posterior border of the ramus of the mandible
The medial pterygoid
The emerging branches of the facial nerve.
17. POSTEROMEDIAL SURFACE:
It is moulded to the mastoid and styloid processes and the
structures attached to them.
The mastoid process, with the sternocleidomastoid and
posterior belly of diagastric.
The styloid process -The external carotid artery enters the
gland through this surface and internal carotid artery lies deep
in the styloid process
19. POSTERIOR BORDER
Separates superficial surface from posteromedial surface
Overlaps sternocleiodomastoid.
MEDIAL BORDER
Separates anteromedial surface from posteromedial surface
Related to lateral wall of pharynx
20. ARTERY
The external carotidartery
The maxillary artery
Superficial temporal vessels
The posterior auricular artery
21. VEINS
The Retromandibular Veins is formed within the gland by the
union of the superficial temporal and maxillary veins. In the lower
part of the gland, the vein divides into anterior and posterior
divisions which emerge at the apex of the gland.
22. THE FACIALNERVE
Enters the gland through the upper part of its posteriomedial
surface, and divides into its terminal branches within the glands.
Branches appear on the surface at the anterior border.
23.
24. Ductus parotideus; Stensen’sduct
It is thick walled and about 5cm long and
5mm in diameter
Carries saliva to the oral cavity.
Course :-
Forms by the union of smaller duct from the gland and
run forwards and slightly downward on the masseter.
25.
26. At the anterior border of the masseter, it turns
medially and pierces:
(a) the buccal padof fat.
(b) the buccalpharyngeal fascia
(c) the buccinator
•“Because of the oblique course of the duct through the
buccinator inflation of the duct is prevented during
blowing.”
27. The duct runs forward for a short distance between the
buccinator and the oral mucosa.
The duct turns medially and opens into the vestibule of
the mouth (gingivo- buccal vestibule) opposite the crown
of the upper molar tooth.
30. SYMPTHETIC SUPPLY- they are vasomotor,
and are derived from the plexus around the
external carotid artery. Its Stimulation produces
thick sticky secretion.
SENSORY NERVES- comes from the
auriculotemporal nerve, but the parotid fascia
is innervated by the sensory fiberes of the great
auricular nerve.
31. The parotid lymph nodes lie partly in the superficial fascia and partly deep
to the deep fascia over the parotid gland.
They drain
the temple
the side of the scalp
the lateral surface of the auricle
theexternal acoustic meatus
the middle ear
the parotidgland
the upper part of cheek
parts of the eyelids and orbit
32. Parotid gland is the largest, provides 65% of the total salivary volume.
Normal outflow is 1-2L/day
Protection of the oral cavity and oral environment: the constant secretion of
saliva prevents desiccation of oral cavity.
Lubrication and cleansing oral cavity: provides a washing action
to flush away debris and non-adherent bacteria and provide
lubrication for smooth and sliding movement.
Initiation of starch digestion: the action of amylase on ingested
carbohydrate to produce glucose and maltose in the mouth.
Immunological: defensive substance in saliva are the immunoglobulin.
The predominant salivary immunoglobulin is IgA.
33. CONGENITAL
Aplasia or atresia- hemifacial microsomia, the LADD
syndrome and mandibulo- facial dysostosis.
Salivary loss leads to increased caries, burning sensation,
oral infections, taste aberrations and difficulty with
denture retention.
38. During the treatment of oral cancer which involves the salivary glands
leading to surgical removal of the glands, leads to decreased or no saliva
secretion.This increases the incidence of dental caries.
Patient under the high dose of radiation therapy reduce the quality and
quantity of normal saliva, causing radiation caries.
Fluoride application
Maintaining the periodontalhealth.
Educating about proper nutrition and good oral
hygiene.
Dentures reconstruction in case of altered oral tissue.
Educating and motivating people about tobacco
cessation.
39. Parotid gland is the largest, it provides 65% of the total
salivary volume.
About 80% of parotid tumour are benign. Surgical
treatment of parotid gland tumour is sometimes difficult
because of its anatomical relation with facial nerve. Thus,
detection of early stages of a parotid tumor is extremely
important.
40. TEXTBOOK OF HUMAN ANATOMY –VOL3;BD
CHAURASIA
TEXTBOOK OF ANATOMY-VOL3;INDERBIR SINGH
PRINCIPAL OF ANATOMY AND
PHYSIOLOGY- TORTORA- DERRICKSON ,12TH
EDITION