This document provides an overview of a presentation on salivary glands. It discusses the classification, composition, functions, and anatomy of salivary glands. It also covers the formation and collection of saliva, conditions affecting salivation, salivary markers for periodontal diagnosis, roles of salivary enzymes and hormones, and the potential for saliva as a future diagnostic fluid. Biomarkers in saliva are classified and salivary substitutes are briefly mentioned.
2. PRESENTATION BY: Dr. Mohamed Abdul Haleem
2nd Year Perio PG
KVG Dental college & Hospital,
Sullia.
3. CONTENTS
1. Introduction
2. Classification of salivary gland
3. Composition of saliva
4. Functions of saliva
5. Properties of saliva
6. Anatomy of salivary gland
7. Salivary gland structure
8. Formation of saliva
9. Collection of saliva
4. CONTENTS
10.Conditions affecting salivation
11.Salivary markers for periodontal diagnosis
12.Role of salivary enzymes
13.Salivary hormones
14.Saliva as a future diagnostic fluid
15.Biomarker
16.Classification of biomarker
17.Salivary substitutes
18.Conclusion
19.References
5. INTRODUCTION
• Glandular tissues of head and neck comprise lacrimal,
salivary, thyroid, parathyroid and thymus glands.
• Salivary glands are of utmost importance to the dentist.
There are three pairs of major salivary glands and
numerous minor salivary glands.
• Their salivary secretion ranges up to 800-1500 ml which
requires 2400 swallows per day.
6. INTRODUCTION
• The oral environment to a large degree is regulated by
saliva.
• Saliva with its unique properties have been implicated not
only in dentistry but also in various other fields of medicine
as a potential diagnostic tool.
7. CLASSIFICATION OF SALIVARY GLAND
1.Based on anatomic location
– Parotid gland
– Sub mandibular gland
– Sub lingual gland
– Accessory glands (labial,
lingual, palatal, buccal,
glossopalatine and retromolar)
2. Based on size and amount of
secretion
– Major salivary glands
– Minor salivary glands
8. 3. Based on type of secretion
– Serous
– Mucous
– Mixed
Parotid glands - Purely serous
Von Ebner’s Glands - Purely serous
Palatine, Glossopalatine - Purely mucous.
Posterior part of the tongue - Purely mucous
Submandibular-Predominantly serous, Mixed
Sublingual - Predominantly mucous , Mixed
Labial, Buccal, Lingual - Mixed
9. COMPOSITION
Parameter Characteristics
Volume 600-1000ml/day
Electrolytes Na+, K+, Cl-, Ca2+, Mg2+and F-
Secretory
proteins/peptides
Amylase, proline-rich proteins, mucins,
histatin, cystatin, peroxidase, lysozyme,
lactoferrin.
Immunoglobulins Secretory immunoglobulins A,
immunoglobulins G and M
Small organic Glucose, amino acids, urea, uric acid, and lipid
molecules
Other components Epidermal growth factor, insulin, cyclic
adenosine monophosphate-binding proteins,
and serum albumin
10. • Saliva is made up of approx. 99% of water.
• Organic components
Protein
200mg/100ml.
enzymes, immunoglobulins, mucins,
traces of albumin and polypeptides
and glycopeptides.
-amylase{Ptyalin}
60-120 mg/100 ml in parotid.
25 mg/100ml in submandibular.
Immunoglobulins
Ig A
Ig G
Ig M
14. PROPERTIES OF SALIVA
• Consistency : Slightly cloudy due to
presence of mucins and other cells
• PH : Usually slightly acidic (5-8), On
standing or boiling, it loses Co2 and
becomes alkaline
• Specific gravity : 1.0024 – 1.0061
• Freezing point :0.07 – 0.34 degree
Celsius
• Osmotic pressure : ( 700-1000m
osmol/litre )
16. Parotid gland
Largest of all the salivary glands
Purely serous gland that produce thin , watery amylase rich saliva
Superficial portion lies in front of external ear & deeper portion
lies behind the ramus of mandible
Stensen's Duct (Parotid Papilla) opens out adjacent to maxillary
second molar.
17. Submandibular Gland
Second largest salivary gland
Mixed gland
Located in the posterior part
of floor of mouth, adjacent to
medial aspect of mandible &
wrapping around the posterior
border of mylohyoid muscle.
Wharton's Duct opens
beneath the tongue at sub-
lingual caruncle lateral to the
lingual frenum.
18. Sublingual Gland
Smallest salivary gland
Mixed gland but mucous
secretory cells predominate.
Located in anterior part of floor
of mouth between the mucosa and
mylohyoid muscle
Opens through series of small
ducts (ducts of rivinus) opening
along the sub-lingual fold & often
through a larger duct (bartholin’s
duct)
19. The minor salivary glands:
1.Estimated numbers is 600-1000.
2.Exist as small, discrete, aggregates of
secretory tissue present in the
submucosa throughout most of the oral
cavity, except the gingival & anterior part
of the hard palate.
3.Predominantly mucous glands, except for
Von Ebners glands (purely serous).
4.Here intercalated & striated ducts are
poorly developed.
20. VASCULAR SUPPLY
PAROTID GLAND
Arterial: Ext.Carotid Artery and its branches
Venous: Ext.Jugular Vein
Lymphatic: Parotid Nodes Upper deep
cervical nodes
SUBMANDIBULAR GLAND
Arterial: Facial Artery , Lingual Artery
Venous: Common Facial Vein /Lingual Vein
Lymphatic: Submandibular Lymph nodes
SUBLINGUAL GLAND
Arterial: Lingual and Submental Arteries
Venous: Lingual Vein
21. INNERVATION
Parasympathetic
innervation to major
salivary glands
Otic ganglion suplies the
parotid gland.
Submandibular ganglion
supplies the other major
glands.
Sympathetic innervation
Promotes the flow of
saliva and stimulates
muscle contraction at
salivary ducts
22. Regulation of salivary secretion
Afferent signals from sensory receptors in mouth
(Trigeminal, facial, glossopharyngeal nerves)
Salivary nuclei in the medulla oblongata of brain
Parasympathetic nerve bundle & sympathetic nerve
bundle
salivary glands
23. Salivary Gland Structure
• Composed of parenchymal elements supported by connective tissue
• The types of cells found in the salivary glands are duct system cells,
acinar cells, mucous cells and myoepithelial cells.
24. • Inter cellular canaliculi : These are the extensions
of the lumen of the end piece between adjacent
secretory cells that serve to increase the terminal
surface area available for secretion.
• Secretory end pieces: branched ducts,
terminating in spherical or tubular secretory end
pieces/ acini.
• Intercalated duct : main duct connecting
acinar/mucous secretions to rest of the gland, not
involved in modification of electrolytes.
• Striated duct: electrolyte regulation in
reabsorbing sodium.
• Excretory duct: continuing sodium reabsorption
and secreting potassium.
25. FORMATION OF SALIVA
Formation of saliva occurs in 2 stages.
Stage 1 : Production of primary saliva from the
cells of secretory end pieces & intercalated
ducts, which is an isotonic fluid
Stage 2 : The primary saliva is modified as it
passes through the striated & excretory ducts
mainly by reabsorption & secretion of
electrolytes. The final saliva that reaches the oral
cavity is hypotonic.
26. Why saliva???
Advantages:
• Non – invasive
• Limited training
• No special equipment
• Potentially valuable for children
and older patients
• Cost effective
• Eliminates the risk of infection
• Easy, No pain, No needle prick,
Fast
• Screening of large population
No Pain
COLLECTION OF SALIVA
27. University of Southern California School of Dentistry
guidelines
• Unstimulated whole saliva collection always should precede
stimulated whole saliva collection.
• The patient is advised to refrain from intake of any food or beverage
(water exempted) one hour before the test session.
• Smoking, chewing gum and intake of coffee also are prohibited
during this hour.
• The subject is advised to rinse his or her mouth several times with
distilled water and then to relax for five minutes.
• Keep his mouth slightly open and allow saliva to drain into the tube.
• Should last for five minutes
28. Unstimulated flow
• Resting salivary flow―no external stimulus
oTypically 0.2 mL – 0.3 mL per minute
oLess than 0.1 mL per minute means the person has
hyposalivation
30. Stimulated Flow
• Response to a stimulus - usually taste,
chewing or medication
oTypically 1.5 mL – 2 mL per minute
oLess than 0.7 mL per minute is considered
hyposalivation
32. PASSIVE DROOL
• Passive drool is highly recommended because it
is cost effective and approved for use with
almost all analytes.
• To avoid problems with analyte retention or the
introduction of contaminants, use only high
quality polypropylene vials for collection, such
as 2 ml cryovials.
• The vials used must seal tightly and be able to
withstand temperatures as low as -80ºC.
33. • Repeat as often as necessary until sufficient sample is collected.
• One mL (excluding foam) is adequate for most tests.
• Collection of samples to be analyzed for multiple analytes may
require larger vials.
34. Salimetrics Oral Swab (SOS)
• Used in participants who are not willing or
able to drool saliva into a vial.
• The saliva samples can be analyzed for
cortisol, testosterone, α-amylase,
chromogranin A, cotinine, C-reactive
protein or SIgA using Oral.
• The SOS also helps filter mucus from the
sample which help improving
immunoassay results.
39. DIAGNOSTIC APPLICATIONS
Serum constituents(i.e., drugs and hormones) reach saliva
through,
– the salivary glands
– GCF outflow
Saliva is used for the diagnosis of:
1. Hereditary Diseases
2. Autoimmune Diseases
3. Malignancy
4. Infectious Diseases
5. Drug Monitoring
6. Monitoring Of Hormone Levels
7. Diagnosis Of Oral Disease With Relevance For Systemic
Diseases
40. DISADVANTAGES
• Samples are subject to bacterial
degradation over time.
• Absorbing specimens on cotton
may contribute interfering
substances to the extract
• Interpretation of saliva assays is
still difficult
• Contamination from bleeding
gums
41. Role of salivary enzymes
• Salivary enzymes can be produced by salivary glands, oral micro
organisms, PMNs, oral epithelial cells or be derived from GCF.
• Attempts have been made to correlate enzymatic activity in human
saliva with periodontal status.
• Studies have also assessed changes in salivary enzyme activity in
response to periodontal therapy.
• Enzymes may alter bacterial receptors & thus affect bacterial
attachment on the tooth (Gibbons & Etherden 1982 ), or they may be
directly involved in the pathogenesis of gingivitis & periodontitis (
Dewar 1958 ).( JPR 1983 18: 559-569 )
42. • Those particularly relevant in this group of enzymes are:
1. Aspartate and alanine aminotransferases (AST and ALT)
2. Lactate dehydrogenase (LDH)
3. Gamma-glutamyl transferase (GGT)
4. Creatine kinase (CK)
5. Alkaline phosphatase (ALP)
6. Acidic phosphatase (ACP)
43. Salivary hormones :
•A workshop on the immunoassay of steroids in saliva concluded that, “
All steroids of diagnostic significance in routine clinical endocrinology
can now be measured in saliva”.
•The list of steroid hormones currently being assayed in saliva includes
cortisol, aldosterone, estriol, testosterone, progesterone etc.
•Salivary estriol measurement during pregnancy has been shown to be
an excellent means of detecting fetal growth retardation & estriol to
progesterone ratio shows promise as a predictor of preterm labor.
•Some investigators have found that salivary cortisol is a better measure
of adrenal cortical function than serum cortisol.
44.
45. What is a biomarker???
• A biomarker is an objective
measure that has been
evaluated and confirmed
either as an indicator of
physiologic health, a
pathogenic process or a
pharmacologic response to a
therapeutic intervention.
46. • Biomarkers, whether
produced by normal healthy
individuals or by individuals
affected by specific systemic
diseases, are tell - tale
molecules that could be
used to monitor health
status, disease onset,
treatment response and
outcome.
49. Locally produced
proteins of host
and bacterial
origin (enzymes,
immunoglobulins
and cytokines)
Genetic ⁄
genomic
biomarkers such
as DNA and
mRNA of host
origin
Bacteria and
bacterial
products, ions,
steroid hormones
and volatile
compounds
Salivary proteomic, genomic and microbial
biomarkers for periodontal diagnosis
50.
51.
52. Salivary proteomic approach as biomarkers
• Periodontopathic bacteria either cause degradation of
host tissue directly or activate a host response
• It initiates the release of biological mediators from host
cells and when it exaggerated it leads to host tissue
destruction
• Mediators include proteinases, cytokines and
prostaglandins. And bacteria-derived enzymes such as
collagen-degrading enzymes, elastase- like enzymes,
trypsin-like proteases, aminopeptidases and
dipeptidylpeptidase
54. • Salivary proteomic biomarkers have been
identified for three key features of the
pathogenic processes in periodontal disease –
– Inflammation
– Collagen degradation and
– Bone turnover
55. Host-derived MMPs
• Both MMP-1 (interstitial collagenase) and
MMP-8 (polymorphonuclear leukocyte-
derived collagenase) gets activated in
periodontitis.
• MMP-8, which is primarily derived from
polymorphonuclear leukocytes during active
stages of periodontitis, is a major tissue
destructive enzyme in periodontal disease
56. • An elevated level of MMP-8 was detected in
the saliva of subjects affected by periodontitis
compared with healthy patients, but the levels
of salivary MMP 1 were similar in both groups.
• Therefore, quantification of the level of MMP-
8 is a promising candidate for diagnosing and,
more importantly, predicting the progression
of this episodic disease.
57. • Other MMPs, including MMP-2, MMP-3 and
MMP-9, were also reported in the saliva of
patients affected by periodontitis
58. • Salivary biomarkers have been used to
examine the effect of lifestyle factors,
including smoking on periodontal health.
• Levels of salivary markers including
prostaglandin E2, lactoferrin, albumin,
aspartate aminotransferase, lactate
dehydrogenase, alkaline phosphatase were
significantly lower in current smokers than in
non-current smokers.
61. Alkaline phosphatase
• Three main sources:
– the actual salivary secretions
– the GCF, PMNs and tissue degradation; and
– disposed bacterial cells from dental biofilms and
mucosal surfaces
62. Alkaline phosphatase
• Significant correlation between ALP and pocket
depth & inflammation exists.
• Higher enzyme activity in individuals with
periodontal disease than non diseased
individuals.
• Periodontal destruction by measurement of
probing depth, gingival bleeding, and suppuration
were related to higher ALP levels in saliva
63. Cathepsin B
• Cathepsin B functions in proteolysis
• 100% sensitivity and 99.8% specificity
• Cathepsin B may have a potential use in
distinguishing periodontitis from gingivitis and
in planning treatment and monitoring
treatment outcomes
64. CRP
• C-reactive protein is a systemic marker released
during acute phase of an inflammatory response
and is produced by liver.
• Circulating CRP reaches saliva via GCF or salivary
glands.
• High levels of CRP are associated with chronic
and aggressive periodontal diseases.
65. Osteopontin (OPN)
• It is a Noncollagenous calcium binding glycosylated
phosphoprotein in bone matrix and is produced by
several cells including osteoblasts, osteoclasts and
macrophages.
• Kido et al (2001) demonstrated that OPN level in
saliva was increased with progression of periodontal
disease.
66. Genomic approach as diagnostic
markers
• Reports of genetic polymorphisms associated
with periodontal disease are increasing and
strong evidence supports the proposal that
genes play a role in the predisposition to and
progression of periodontal disease.
67. • A number of studies have examined links
between polymorphisms within host response
factors and aggressive periodontitis.
• By examination of the genes encoding
inflammatory cytokines such as IL-1 and TNF
α, the anti-inflammatory cytokine IL-10 and
the F c- gamma receptors.
68. • Reactive oxygen species, participate in the
pathogenesis of periodontal tissue destruction.
• DNA damage, lipid peroxidation, protein
disruption and stimulation of inflammatory
cytokine release.
• 8-hydroxy-deoxyguanosine - a product of
oxidative DNA damage, is a biomarker for
detecting periodontitis in human subjects.
69. • Till now,68 up-regulated and six down-
regulated genes was identified, including
lactotransferrin, MMP-1, MMP-3, interferon
induced-15, keratin 2A and desmocollin-1, and
this result was confirmed by real-time
polymerase chain reaction.
70. Stress biomarkers in saliva
• Salivary α-amylase
• Chromogranin A
• Salivary cortisol
71. Salivary cortisol
• Its level in saliva is lower than that in blood
• Advantage of salivary over serum cortisol
measurement is the minimisation of stress
from fear of needles during collection, which
may bias the results.
72. Salivary – α amylase &
Chromogranin A
• Both salivary CgA and a-amylase are
considered biomarkers of the stress response
by the sympatho–adreno–medullary system,
unlike cortisol, which is considered a
biomarker of stress response by the
Hypothalamic pituitary adrenal system.
73.
74. Various other diagnosis
• Candidiasis
• Risk of cardiovascular and cerebrovascular diseases
• Cystic fibrosis
• Oral squamous cell carcinoma
– protein p53
– M2BP
– MRP14
– CD59
– Profilin
– Catalase
• Breast and ovarian cancer
75. • PCR detection of H. pylori in the saliva show high
sensitivity.
• The presence of antibodies to other infectious
organisms such as Borrelia burdogferi, shigella
can also be detected in saliva.
• Detection of hepatitis A and hepatitis B surface
antigen in the saliva has been used in
epidemiological studies.
76. • In neonates the presence of Ig A is an
excellent marker of rota virus infection
• HIV antibody detection is as precise in saliva
as in serum and is both applicable in clinical
and epidemiological studies.
79. Drug monitoring in saliva
Used to check:
• Molecular size
• Lipid solubility
• The degree of ionization of the drug
• The effect of salivary Ph
• The degree of protein binding of the drug
81. Saliva and age
• With age, a generalized loss of salivary gland
parenchymal tissue loss is seen.
• Salivary acini are replaced by adipose tissue.
• Decreased production of saliva
82. RESEARCH APPLICATIONS
Research currently is being conducted to:
• To find more details on saliva as a diagnostic aid for
cancer and preterm labor.
• Check regenerative properties and functions of
growth factors found in saliva, such as EGF, TGF
83. • Saliva is an alternative to serum as a biological fluid that can be
analyzed for diagnostic purposes.
• A number of markers show promise as sensitive measures of the
disease & the effectiveness of therapy are well co-related.
• Longer - term longitudinal studies , however are required to
establish the relationship between specific markers &
progression of periodontal disease.
• Further more, analysis of saliva may offer a cost effective
approach to assessment of periodontal disease in large
populations.
CONCLUSION
84. 1. Clinical Periodontology 10th Edition; Carranza,Newmann.
2. Shafers textbook of oral pathology. 5th Edtn
3. Burkitt’s textboof of oral medicine. 11th edtn
4. Periodontology 2000 volume 34: 2004
5. Tencate’s Oral histology 6th edition
6. J. Clinical Periodontology 2003;30:752-755
7. J. Clinical Periodontology 2000,27:453-465
8. J. Periodontal Research 1990,1983
9. J. Oral Pathology Medicine 1990.
10.Dentomaxillofac Radiol 2007;36:59-62. T Bar, A Zagury, D London, R
Shacham, and O Nahlieli.
REFERENCES