3. INTRODUCTION
• Saliva reflects the physiological state of the body including emotional,
endocrinal, nutritional and metabolic variations of thebody
• Saliva is a complex fluid.
• Saliva circulating in mouth at any given time is termed “whole
saliva”.
Whats this
4. According to Stedmen’s Dictionary
Saliva is a clear, tasteless, odourless slightly acidic (pH6.8), viscid fluid, consisting
of secretions from the parotid, sublingual and submandibular salivary gland
and the mucous glands of the oral cavity.
5. Whole saliva is derived from 3 pairs of major salivary glands (90% of
total saliva secretion)& Minor salivary glands
Whole saliva contains gingival crevicular fluid, micro organisms from
dental plaque, food debris
6. • In resting phase- 2/3rd of whole saliva
produced by submandibular glands
• When stimulated- atleast ½ of whole saliva by
parotid
• Only small % of stimulated & unstimulated
whole saliva comes fromsublingual glands
8. CLASSIFICATION OF SALIVARY GLANDS
MAJOR
SALIVARY
GLANDS
Parotid
Gland
Submandibular
Gland
Sublingual
Gland
MINOR
SALIVARY
GLANDS
Lingual
Retromolar
Buccal glands
Labial glands
Palatal glands
Blandin/ nuhn
glands
von ebners
glands
According to size and location
9. Based on type of secretion
– Serous
– Mucous
– Mixed Parotid glands - Purely serous
Von Ebner’s Glands(lingual) - Purely serous
Submandibular-Predominantly mucuos, Mixed
Sublingual - Predominantly mucous , Mixed
Labial, Buccal, retromolar - mainly Mucous , Mixed
Palatine- Purely mucous.
10. DEVELOPMENT of salivary glands
ORAL EPITHELIAL BUDS
ECTODERM ENDODERM
PAROTID GLAND AND MINOR
SALIVORY GLANDS
SUBMANDIBULAR AND
SUBLINGUAL GLAND
All salivary glands showsimilar pattern of development
11. • As the salivary glands develop near the junctional area between the ectoderm of the
foregut, it is difficult to determine whether they are ectodermal or endodermal.
• The outgrowth for the parotid gland arises in relation to the line along which the
maxillary and mandibular process fuse to form the cheek. it is generally considered
as ectodermal.
• The outgrowths for the submandibular and sublingual glands arise in relation to the
linguo-gingival sulcus. They are usuallyconsidered to be of endodermal origin.
12. • The parotid are the first to develop, followed by the submandibular gland, and finally the
sublingual gland.
• Parenchymal tissue (secretory) of the glands arises from the proliferation of oral
epithelium.
• The stroma (capsule and septae) of the glands originates from mesenchyme that may be
mesodermal or neural crest in origin
• Although the parotid are the first to develop, they become encapsulated after the SMG
and SLG.
13. The Primordia of the glands of humans appear
during sixthweek .
The minor salivary glands begin their
development during the third month.
They arise as epithelial buds in the oral cavity
& extends into underlying mesenchyme(bud
stage)
14. • The epithelial buds of each glandenlarge, elongate andbranch initially
forming solid structures.(cordstage)
• Branching of the glandular mass produces arborization.(a fine branching
structure)
• Each branch terminates in one or two solidend bulbs.( terminal bulb stage)
15. • Elongation of the end bulb follows and lumina appears in their centers,
transforming the end bulbs intoterminal tubules. ( lobule stage)
• These tubules join the canalizing ducts to the peripheral acini. (duct
canalization)
• Canalization is complete by 6th month post conception.
• Finally cytodifferentiationbegins following canalization..(dev of specialized cells)
16.
17. – Largest of salivary glands
Wt – 15g
a three sided pyramid
Withapexdirecteddownwards.
Has large superficial & small deeplobes- divided by facial nerve
4 surfaces (superficial, superior, anteromedial, posteromedial) & 3 borders( ant, post, medial).
Accessory parotid– a part of forwardextension, often detached.
19. Capsule of parotidgland:
• The deep cervical fascia forms a capsule for a gland
• The fascia splits between angle of mandible & mastoidprocess to enclose the gland
Superficial lamina: thick, adherent to gland attached above zygomatic arch
Deep lamina: thin, attachedto the styloidprocess, tympanic plate, the angle & ramus of
mandible.
A portion of deep lamina extending between the styloidprocess& mandible is thickened
to formstylomandibular ligament.
20. Structures within parotidgland
Arteries: external carotidartery
maxillary artery
superficial temporal artery
transverse facial artery
Veins: retromandibular vein is formed by union
of superficial temporal & maxillaryveins
In the lower part of gland the vein divides into ant
& post divisons & emerges
Nerve : facial nerve divides into its terminal
branches
facial nerve lies in relationto isthmus of the gland
21. Parotid duct:
• It is thick walled
• 5cm long
• Emerges fromthe middle of the ant border of gland
• The duct runs forward for a short distance between
buccinator and oral mucosa
• Then the duct turns medially and opens into the
vestibule of mouth
22. • Blood supply:
parotid gland supplied by the external
carotid artery & its branches
Veins drain into ext & internal jugular
veins
• Lymphatic drainage:
Lymph drains first to parotid nodes then
upper deep cervical nodes
Parotid lymph nodes lie partly in the
superficial fascia and partly deep to the deep
fascia
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23. Nerve supply:
Parasympathetic nerves- are secreto motor, reach
gland through the auriculotemporal nerve.
Sympathetic nerve supply – Plexus around middle
meningeal artery
Sensory nerves to the gland- auriculotemporal nerve
to the parotid fascia- sensory fibers of
the greater auricular nerve
Tympanic
branch
Tympanic
plexus
Foramen
ovale
Leser
petrosal
nerve
Inf sn
24.
25. • Situated in the anterior part of digastric triangle
• Size of walnut
• Roughly J shape
• Two parts by mylohoid muscle
• larger superficial and small deep part
• Partially Enclosedbetween 2 layers of deep cervical fascia
• Superficial layer of fascia covers inferior surface of gland & attached to base of mand
• Deep layer cover medial surface of gland & is attachedto mylohoid line of mand
Submandibular duct
Superficial part
Deep part
26. Superficial part:
• fills digastric triangle
• Extends upwards deep the mandible upto mylohoid line
• It has 3 sufarces inf, lat & medial
• Medial surface- mylohyoid, hyoglassus, styloglossus mus
• Inferiorly overlaps stylohyoid & post bellyof digastric
• Lateral surface- facial artery,
Submandibular fossa on mand
insertion of medial pterygoid
Deep part- small in size. anteriorly extends upto the post end of sublingual gland.
Deep to the mylohyoid, & superficial to hyoglossus & styloglossus muscle
27. SUBMANDIBULAR DUCT /
WHARTON’S DOCT:
• Thin walled& 5 cm long
• Emerges at ant end of deep part of
the gland
• Runs between lingual & hypoglossal
nerves
• Opens on the floor of the mouth on
the summit of sublingual papilla, at
the side of frenulumof tongue.
28. Blood and lympatic drainage
Arterial supply
• Cervical part of facial artery fromexternal carotid art
• The artery makes an s-bend (two loops) first winding
down over the sub mand gland then up over the base
of mandible
Veins: vein drain into common facial or lingual vein
Lymph passes to submandibular lymphnodes.
29.
30. • Lies in the sublingual fossa on the base of the
mandible
• Smallest of the 3 paired salivary glands
• Weighs about 3 to 4 gms
• Not enclosed by fascia
• Mainlymucus secreting
• About 15 ducts emerge from the gland – most of them
open directly on the summit of sublingual fold. Few of
themjointhe submandibular gland
31. Relations :
• Front – meet with opp side gland
• Behind- comes in contact withdeeper part of sub mand gland
• Above- mucous membrane of mouth
• Belowmylohyoid muscle
• Lateral- sublingual fossa
• Medial – genioglossus muscle
• Bloodsupply-
lingual & submental arteries
32. Nerve supply: similar for both submand & sub lingual
glands
• Suppliedby branches fromsubmandibular ganglion
• Thesebranches convey
a. Parasympathetic fibers are Secretomotor, post ganglionic
fibers reach gland through 5 or 6 branches from
submandibularganglion
b. Sensoryfibers reach ganglionthrough the lingual nerve
c. Vasomotor sympathetic fibers from plexus on the facial
artery. It contains post ganglionic fibers arising in the
superiorcervical ganglion
Superior salivatory nucleus
Nervus intermedius
Facial nerve
Chorda tympani
Joins lingual nerve,
branch of mand nerve
Submandibular ganglion
Sub mand & sub ling glands
Post ganglionic fibers
34. Minor Salivary gland:
• Continuous slow secreting glands, thus have a important role in protecting and
moisteningoral mucosa.
• No. between 600 and 1000.
• Exist as aggregates of secretory tissue present in submucosa throughout most of the
oral cavity.
• Not seen in gingiva & anterior part of hardplate.
• Rich in mucin, antibacterial proteins and secretory immunoglobulin.
34
35. LINGUAL MINOR GLANDS
Von Ebners’s Lingual serous gland:
• Located in tongue open into the troughs surrounding circumvallate papillae on the
dorsumof tongue and at the foliatepapillae on the side of tongue.
• Secrete digestive enzymes & proteins that are thought to playrole in taste process
• Fluid of their secretion cleanse the trough & prepare the taste receptors for a new
stimulus.
Blandin or nuhn glands mucous gland: situated on the under surface of the apex of the tongue on
either side of frenulum.
35
36. Nerve supply of minor salivary glands
• Palatinal – facial nerve
• Buccal – facial nerve
• Labial are supplied by facial nerve
• Lingual are supplied by glossopharyngeal nerve
• Retro molar supplied by both facial & IX nerves
37. Structure of salivary glands
• The working parts of the salivary glandular tissue
consist of the secretory end pieces (acini) and the
branched ductal system.
• In serous glands (e.g. the parotids) the cells in the
end piece are arranged in a roughly spherical form.
• In mucous glands, they tend to be arranged in a
tubular configuration witha larger central lumen.
38. • In both types of gland the cells in the end piece surround
a lumenand this is the start of the ductal system.
• There are three types of duct present in all salivaryglands.
– Intercalatedduct
– Striated duct
– Excretoryduct
39. The fluid first passes through the
intercalated ducts which have low cuboidal
epithelium and a narrow lumen.
From there the secretions enter the striated
ducts which are lined by more columnar
cells with many mitochondria.
Finally, the saliva passes through the
excretory ducts where the cell type is
cuboidal until the terminal part which is
lined with stratified squamous epithelium.
40. • End pieces may contain mucous cells, serous cells or
a mixture of both.
• A salivary gland can consist of a varied mixture of
these types of end pieces.
• In mixed glands, the mucous acini are capped by a
serous demilune. (secrete proteins that digest cell
membrane of bacteria)
• In addition, myoepithelial cells surround the end
piece, their function being to assist in propelling the
secretion into the ductal system.
• The gland and its specialised nerve and blood
supply are supported by a connective tissue stroma.
41. Serous acini
1. Samller in size,rounded in shape.
2. Lumenhardlyvisible.
3. Lining cells pyramidal in shape and relativelymore
in number.
4. Nuclieare round and basal.
5. Cytoplasmdepicts basalbasophiliaand apical
eosinophilia.
6. May present as demilunes on one aspect of some
mucousacini
Mucous acini
1. Larger in size , more variable in shape.
2. Lumenmostly visible.
3. Lining cells truncatedcolumnar in shape.
Cells relatively fewer in number.
4. Nuclie are flattenedand peripheral.
5. Cytoplasmis pale and vacuolated.
6. Mucous acini only present as complete acini.
42.
43. Types of Saliva
• salivary glands, theircells and ducts are greatly responsible for the
modification andkindof saliva being secreted
• It is of three types:
– Serous Saliva
– Viscous Saliva
– MixedSaliva
44. Serous Saliva
• Content:
– Amylase protein
– polysaccharides
• Cell: Serous Cells
• “watery saliva”
• Glands that secrete this type:
–ParotidGland
–VonEbner’sglands
45. MUCOUS SALIVA
• Content:
– Mucins (glycoproteins)
– Carbohydrates
• Cell: Mucous Cells
• Thick and viscous
• Glands that secrete this type:
• Sublingualsalivarygland,palatine, retromolarminorsalivaryglands
46. MIXED SALIVA
• simplythe combination of the aforementionedtypes of saliva
• Secretedby:
SubmandibularGland(mainlymucous)
Retromolar (mainlymucous)
Buccal, labialareseromucouss
Cells:
– Serous Cells
– Mucous Cells
47. Secretion of saliva
• Although fluid secretion occurs only through the acini, proteins are produced and
transportedinto the saliva through both acinar and ductal cells.
• The primary saliva within the acinar end pieces is isotonic with serum but undergoes
extensive resorption of sodium and chloride and secretion of potassium within the duct
system.
• The saliva, as it entersthe oral cavity, is a protein-rich hypotonicfluid.
• Blood supply & nerve control of salivary glands is important for saliva production
48. Fluid in saliva originates fromthe capillaries & interstitial fluid
• This blood supply is organised as portal system with two
capillary networks, a dense one around duct system, &
another around secretory end piece
• Blood vessels of the SG are controlled by sym NS, which
makes themconstrict
• However parasympathetic stimulation induces formation of
Vasoactive intestinal polypeptide
Nitric oxide that are released by SGs
48
BLOOD SUPPLY OF SALIVARY GLANDS
49. • The secretion of saliva is regulated by Autonomic NS.
• Reflex pathway is unilateral
• Stimulationon one side induces ipsilateral salivation
• The act of chewing & sensation of taste initiateaction potentials in various receptors
1. Masticatory salivary reflex involves sensory inputs mainly from mechanical receptrs
in mouth
These include mechanoreceptors in PDL, proprioceptors in the trigeminal innervation
including musclespindles in the masticatory muscles & oral nociceptivestimuli
2. The gustatory salivary reflex utilizes sensory signals from taste activated
chemoreceptors in the tastebuds
NERVOUS CONTROL OF SALIVARY SECRETION
50. • These signals are conducted along VII, IX, X nerves to salivatory nuclei
• Here the signals activate secretomotor pathways of reflex that consist of sym & para
symnerve bundles
• They travel along separate pathways to the salivary glands
• Selective parasympatheticor symstimulation of SGs elicit secretion
• the autonomic nerve endings release neurotransmitters
• These include Ach, noradrenaline, adenosine triphosphate, substance P, vaso active
intestinal polypeptide, neuropeptide Y.
51. • These neuro transmitters activates specific cell surface membrane receptors on the
salivary gland
• They also have modulatory effect on formation of saliva, there by determining flowrate
& composition of saliva
• The parasympathetic branch provides the main stimulus for salivation giving rise to
highflow rate of watery saliva
• Sympathetic stimulation leads to lower flow rate , much more viscous (high mucin)
• All the reflexes mentioned above are unconditioned reflexes
• Salivary secretion can also be initiated by cond.reflexes that are programmed in
higher centers in brain
52. Factors effecting salivary flowrate:
• Emotional state( anxiety- inhibition)
• Salivation can also be diminished in untreateddepression
• Acidic taste- max stimu, sweet- less stimulation
• During sleep- salivary secretion frommajor glands very low
• Positive experiences with foodin the past- increases salivation
Therefore many signals from variety of peripheral receptors & from higher centers of
brain are being constantly integrated in salivatory nuclei, the result of which may either
facilitate or inhibit salivation
53. Flow rate (ml/min) of saliva
WHOLE PAROTID SUBMANDIBULAR
RESTING 0.2-0.4 0.04 0.1
STIMULATED 2.0-5.0 1.0-2.0 0.8
pH 6.7-7.4 6.0-7.8
53
0.0
0.1
0.2
0.3
0.4
0.5
20-39 yr 40-59 yr > 60 yr
ml/min
Age
Flow Rate of Saliva
unstimulated
stimulated
54. • Thaysen & colleagues- secretion model for formation of
saliva
• Salivais formedbasically in 2 steps
1. Secretory end piece produces primary saliva(isotonic)
2. Fluid is then modifiedin the duct system
a) selective reabsorption of NA & CL
b) certain secretion of K & HCO3
• Thus Secretion rate and volume of the final saliva is
determined by the formation of primary saliva by the
acinar cells
Formation of saliva
55. Stimulus – secretion coupling:
• The secretion of electrolytes, water & exocytotic release of proteins from the acinar
cells depends upon stimulation, involving multitude of biochemical signalling
processes
• The key event is the rise in the free intra cellular Ca conc in the acinus
• This is initiated by specific activation of receptors in the plasmamembrane by
neurotransmitters.
• Thisreceptor induced rise in ca conc involves different signalling routes
56. Ach
Muscarinic cholinergic receptors
NA
Alpha1 cholinergic receptors
Binding induces phospholipase C- mediated hydrolysis of phosphatidylinositol 4,5 bisphosphate(PIP2)
Inositol 1,4,5 triphosphate (IP3)
(watersoluble)
Diacylglycerol(DAG)
Binds to IP3 receptors on
endoplasmic reticulum
Induces ca release from this store
within cell
1
Activates protein kinaseC
Protein synthesis and secretion
57. 2 Noradrenaline (Gs protein & adenylate cyclase)
Synthesis of cAMP
Activates protein kinase A
Protein synthesis in
the rough ER
Exocytosis of protein containing
secretory granules across
cell membrane
rise in intracellular ca
• Protein secretion from the SG tissue is continuous so called constitutive exocytosis of protein vesicles
• Constitutive exocytosis can be accelerated to regulatory exocytosis by appropriate firing impulse frequency
& specific receptor activation of salivary gland
• This regulatory exocytosis is controlled by sym & para sym secretomotor innervation
• Minor glands secrete a protein rich (mucin ) secretion continuously.
58. Electrolyte transport of acinar cells:
The plasma membranes of the acinar cells are freely permeable to water and to lipid
soluble substances, but not to ions
• Thus electrolyte transport across the plasma membrane must occur through specific
transport mechanism such as ion channels, pumps, cotransporters & exchange
systems
• The general principle behind the formation of primary saliva is the increase in
intracellularfree Ca by losing
K to interstitium&
CL to lumen via activated ca regulated K & CL channels.
59. • The accumulation of CL in lumen creates negative intracellular potential
• This drives interstitial Na into the lumen ( via cation selective tight junctions) to
preserveelecroneutrality.
• A transepithelial water flux occurs probably by trans & paracellular pathways, due to
net movement of salt into the lumen osmotically
• This results in acinar cell shrinkage ( by water loss via water channels aquaporins) &
formationof isotonic, plasma like primary saliva.
60. initial receptor activation of acinar cell
Loss of K , CL, water
from acinar cells
Increase in na conc by
downhill influx
Activation of Na/ H exchange
Na/ K/ 2CL cotransporer
or
Activates cell membrane element,
Na/K pump (ATPase)
This active mechanism then utilizes energy in the form of ATP, then re-estlabish the
Original Prestimlatory(unstimulated) ion gradients across the acinar plasma membrane by
active uphill extrusion of Na & influx of K
61. • Similarly the prestimulatoryacinar CL conc is re-establishedby uphill influx of the Cl ion
• This influx of CL occurs through CL/ HCO3 exchangers ( parallel with Na/H exchange) &
Na/K/2CLCotransporters
• Osmosis causes water to follow the inward movement of ions & cell swells back to its
prestimulatory volume
When stimulus removed, the free intracellular ca conc, the cytoplasmicPH, the cell volumes,
the activity of Transporters including ionchannels return the their original prestimulatory levels &
the acinus is againreadyto produce substantial amounts of primary saliva.
62. Ductal modification of electrolyte
• Sym & para sympathetic nerve fibers control the activity of salivary ducts in the
secretoryend piece
• The membrane transporters and the cell signalling mechanisms of the duct cells are
similar to those of acinar cells.
• These transporters are most important for the modification of primary saliva in ducts
• Stimulation of receptors in the duct cells by neurotransmitters and peptides induce
rise in intracellular free Ca concentration & cyclic AMP
63. • Most of the Na reabsorption from primary saliva occurs across the luminal
membrane in the infoldings of the striated duct by ATP- consuming Na / K pumps
• The pump mechanism maintains extrusion of Na from duct cell to the interstitium
and ductal uptake of K
• This creates an inwardly directed Na gradient allowing Na to pass into duct cell from
primarysaliva.
• The uptake of Na is balanced by parallel uptake of CL via CL channels & CL/HCO3
exchangemechanisms
64. • Secrection of K intosaliva occursto preserve electro neutrality.
• Because of low water permeability of the duct , the final saliva secreted into mouth
becomes hypotonic to plasma with much lower conc of Na & CL than primary saliva
65. Composition of saliva
The final composition of saliva arising from major salivary glands secreted into mouth is hypotonic
relative to plasma
More than99%water and less than1% dry matter
Depending on flow rate
Whole saliva – 3-6 times less electrolytes thanplasma
As flow rate inc – dramatic inc in NA+, CL-, HCO3-
Stimulatedsaliva is less hypotonicthanunstimulated saliva
Stimulatedsaliva contains more higher concof HCO3- than unstimulated saliva.
66. Solid present in saliva consists:-
• Cellular constituents – consist of yeast, bacteria, protozoa, polymorpho nuclear
leukocytes and desquamated epithelial cells.
• Inorganic ions- major(Na+ ,k+ ,Cl-,HCO3-) and Minor (Ca++ ,Mg++ ,HPO4-, bromide
and F-)
• Secretory proteins and glycoproteins – various enzymes, large carbohydrate rich
protein or mucin, antibacterial substance, group of protein's involvedin enamel.
• Serum constituents- albumin, blood clotting factor , B2 microglobulin and
immunoglobulin.
67.
68. • Normal stimulated flow of saliva- for different ages
can be calculated by the equation:-
0.78 * age + 5.6 = stimulated flow / 15 min
5.6 – it is stimulated flow of the infants
69. Functions of salivaFunction Action
Fluid/Lubricant Saliva contains mucins that are glycoproteins, contains more than 40% carbohydrate.
They have lubricating functions on oral tissues. Coats hard and soft tissue which helps
to protect against mechanical, thermal and chemical irritation and tooth wear. Assists
smooth air flow, speech and swallowing.
Ion reservoir Saliva is supersaturated with respect to hydroxyapatite, the main composition of teeth.
This facilitates remineralisation of the teeth. Statherin and acidic proline-rich proteins in
saliva inhibit spontaneous precipitation of calcium phosphate salts.
Buffer The ability of saliva to maintain the PH when exposed to food(acid) is termed buffer
capacity. thus reducing time for demineralisation. The bicarbonate buffer system has
highest contribution. Other include phosphate Bsys, protein Bsys,
Cleansing The clearance is mainly due to flushin effect of salivaClears food and aids swallowing.
Antimicrobial actions Specific (e.g. sIgA) and non-specific (e.g. Lysozyme,Lactoferrin and Myeloperoxidase)
anti-microbial mechanisms help to control the oral microflora. The secretory salivary IgA
is a specific defence factor i.e stimulated in the presence of bacteria. Some studies
have shown protective effect of IgA against dental caries
Agglutination Agglutinins in saliva aggregate bacteria, resulting in accelerated clearance of bacterial
cells. Examples are mucins and parotid saliva glycoproteins.
70. Pellicle formation Thin protective diffusion barrier formed on enamel from salivary and
other proteins. The proteins include in formation of pellicle includes
acidic proline rich protein, Ig-a, cystatin, lactoferrin, lysozyme &
amylase. This acquired pellicle may favour non harmful colonization
pattern & further protect teeth.
Digestion The enzyme α-amylase is the most abundant salivary enzyme; this
enzyme hydrolyses the alpfa-1,4-glycosidic linkages of starch. These
are secreted from serous cells. Amylase is active above PH 6. it splits
starchy foods into maltose, malto-triose and dextrins. In infants and
pancreatic dysfunction it is of major importance
Taste Saliva acts as a solvent, thus allowing interaction of foodstuff with
taste buds to facilitate taste
Excretion As the oral cavity is technically outside the body, substances which
are secreted in saliva are excreted. This is a very inefficient excretory
pathway as reabsorption may occur further down the intestinal tract.
Water balance Under conditions of dehydration, salivary flow is reduced, dryness of
the mouth and information from osmo-receptors are translated into
brain. This causes decreased urine production and increased drinking.
Wound healing effect Epidermal growth factor is a small protein found in SMG, parotid
gland, whose output increases during mastication. EGF
enhances healing of ulcers & plays imp role in esophageal
mucosal protection
71. „APPLIED PHYSIOLOGY
HYPOSALIVATION
• Reductionin the secretion of saliva is called hyposalivation.
• It is of two types, namely temporaryhyposalivationand permanent hyposalivation.
1. Temporary hyposalivationoccurs in:
i. Emotional conditions like fear.
ii. Fever.
iii. Dehydration. .
Permanent hyposalivation occurs in:
i. Sialolithiasis (obstruction of salivary duct).
ii.Congenital absence or hypoplasia of salivary glands.
iii. Bell palsy (paralysis of facial nerve).
72. HYPERSALIVATION
• Excess secretionof saliva is known as hypersalivation.
• Physiological condition when hypersalivation occurs is pregnancy. Hypersalivation in
pathological conditions is calledptyalism, sialorrhea, sialismor sialosis.
• Hyper salivationoccurs in the following pathological conditions:
1. Decay of tooth or neoplasm (abnormal new growth or tumor) in mouth or tongue due
to continuous irritation of nerveendings in the mouth.
2. Disease of esophagus, stomach and intestine.
3.Neurological disorders such as cerebral palsy, mental retardation, cerebral stroke and
parkinsonism.
4.Some psychological and psychiatric conditions.
5.Nausea and vomiting.
