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Presented by : Dr. Vini MehtaMDS 1St Year

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Contents• Introduction• Development of Salivary Glands• Classification of Salivary Glands• Formation of Saliva• Composition of Saliva• Functions of Saliva• Co relation between Saliva and Dental Caries• Factors affecting flow of saliva• Saliva as Diagnostic Aid• Saliva and Oral Health• Saliva Collection Methods• Conclusion

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Introduction

• The oral cavity is a moist environment; a film of fluid called saliva constantly coats its inner surfaces and occupies the space between the lining oral mucosa and teeth.

• Saliva is a complex fluid, produced by the salivary glands, whose important role is maintaining the well being of mouth.

• Saliva is referred to as the “AQVA VITA” of mouth

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Development of Salivary Glands•Salivary glands are made up of cells which are arranged in small groups around a central globular cavity called acinus & alveolus.•The central cavity is continous with the lumen of the duct. •The fine duct draining each acinus is called the intercalated ducts.•Many intercalated ducts join together to form intralobular ducts.•Two or more intralobular ducts join to form interlobular ducts , which unite to form the main duct of the gland. •The gland with this type of structure & duct system is called racemose type.

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Classification Of Salivary Glands

Major Salivary Glands

Parotid Gland

Submandibular Gland

Sublingual Gland

(a)According to size and location

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MAJOR SALIVARY GLANDSPAROTID GLAND• Parotid gland is the largest salivary gland. It is irregular, wedge

shaped and unilobular.• 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 opens out adjacent to maxillary second molar.

Parotid gland

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Submandibular Gland

• Also called as Submaxillary gland.• It is irregular and Walnut shaped.• Second largest• It is 10-15gms in weight,produces 60-

65% of total salivary volume.• Located in the submandibular

triangle of the neck, inferior & lateral to mylohyoid muscle.

• Mixed gland• Wharton's Duct opens beneath the

tongue

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SUBLINGUAL GLAND• The sublingual glands are the

smallest of the major salivary glands, produces 2-5% of the total salivary volume.

• Almond shaped • Glands lie beneath mucosa of

floor of the mouth, above mylohyoid muscle , medial to mandible and lateral to genioglossus

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(b) According to the histochemical nature of secretory products.

•This type of gland is made up of serous cells predominantly. •These glands secrete thin & watery saliva . •Parotid glands and lingual glands are serous glands.

SEROUS GLANDS

•This type of glands are made up of mucous cells mainly . •These glands secrete thick & viscous saliva with more mucin .•Lingual mucous, buccal glands & palatal glands belongs to this type.

MUCOUS GLANDS

•Mixed glands are made up of both serous and mucous cells .•Submandibular , sublingual & lacrimal glands are mixed glands

MIXED GLANDS

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(c) Depending on the number of ducts

Monostomatic• Parotid glands• Submandibular glands

Polystomatic• Sublingual glands

(Duct of revinus & Bartholine duct)

Resting flow of saliva • Under resting condition , without the exogenous stimulation

associated with feeding , there is a slow flow of saliva which keeps the mouth moist and lubricates the mucous membrane.

• This unstimulated flow , which is present most of the time is very important for the health and well being of the oral cavity

• Basal or the ‘unstimulated’ salivary flow is considered to be a protective secretion while the large stimulated flow is needed to facilitate the digestive process

(food bolus formation & swallowing).

SALIVA FLOW RATE

• Resting flow rate 0.3-0.4 ml/min

• Stimulated flow rate 1-2 ml/min 5.6 ml in infants

Physical properties

• Approx. daily secretion of saliva 1.5 lts• 20-25% parotid glands• 60-65% submandibular glands• 7-8% sublingual glands• pH 6.7-7.4• Specific gravity 1.002-1.012• Freezing point : 0.07 to 0.34 degree C

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Formation of SalivaFormation 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.

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Composition ofSaliva

Water -99.5% solids 0.5%

Organic substance Inorganic substance

Gases

Enzymes Other org. substance

1.Amylase 2.Maltase 3.Lingual

lipase 4.Lysozyme 5.carbonic anhydrase 6.kalikrein

1.Proteins- mucin & albumin

2.Blood group antigen3.Free amino acids

4.Non protein nitrogenous

substances-urea, uric acid, creatinine

1.Sodium2.Calcium

3.Potassium4.Biocarbonate

5.Bromide6.Chlorine7.Fluoride

8.phosphate

1.Oxygen2.Carbon dioxide

3.Nitrogen

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Whole Saliva

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Functions of SalivaFunctions Effect Active constituentsProtection Lubrication , Pellicle

formationGlycoprotein , Water

Buffering Maintains pH , Neutralizes acid

Phosphate and bicarbonates

Digestion Bolus formation , digest starch

amylase , lingual lipase

Taste Solution of moleculesTaste and growth & Maturation of taste buds

Water , gustin

Anti microbial action Barrier , antibodies , hostile environment

Glycoprotein , IgA , Lysozyme , Lactoferrin

Tooth integrity Enamel maturation , Repair

Calcium , Phosphate

Protection and lubrication• Saliva forms a seromucosal covering that lubricates

and protects the oral tissues against irritating agents.• This occurs due to mucins (proteins with high

carbohydrate content) responsible for lubrication, protection against dehydration, and maintenance of salivary viscoelasticity.

• They also selectively modulate the adhesion of microorganisms to the oral tissue surfaces, which contributes to the control of bacterial and fungal colonization.

Buffering capacity

• Saliva behaves as a buffer system to protect the mouth as follows:

1. It prevents colonization by potentially pathogenic microorganisms by denying them optimization of environmental conditions.

2. Saliva buffers (neutralizes) and cleans the acids produced by acidogenic microorganisms, thus, preventing enamel demineralization

Buffering capacity

• The carbonic acid-bicarbonate system is the most important buffer in stimulated saliva, while in unstimulated saliva it serves as the phosphate buffer system

• Sialin, a salivary peptide, plays an important role in increasing the biofilm pH after exposure to fermentable carbohydrates

• Urea is another buffer present in total salivary fluid which is a product of amino acid and protein catabolism that causes a rapid increase in biofilm pH by releasing ammonia and carbon dioxide when hydrolyzed by bacterial urease

Diluting and cleansing

• In addition to diluting substances, its fluid consistency provides mechanical cleansing of the residues present in the mouth such as nonadherent bacteria and cellular and food debris.

• SF tends to eliminate excess carbohydrates, thus, limiting the availability of sugars to the biofilm microorganisms.

Integrity of Tooth Enamel

• Saliva plays a fundamental role in maintaining the physical-chemical integrity of tooth enamel by modulating remineralization and demineralization.

• The main factors controlling the stability of enamel hydroxyapatite are the active concentrations free of calcium, phosphate and fluoride in solution and the salivary pH

• The high concentrations of calcium and phosphate in saliva guarantee ionic exchanges directed towards the tooth surfaces that begin with tooth eruption resulting in post-eruptive maturation.

EFFECT OF DRUGS & CHEMICAL ON SALIVARY SECRETION

1) Sympathomimetic drugs like adrenaline & ephedrine stimulates salivary secretion

2) Parasympthomimetic drugs like acetylcholine , pilocarpine & physostigmine increase the salivary secretion

3) Histamine stimulates the secretion of saliva4) Parasympathetic depressants like atropine inhibit the

secretion of saliva5) Anaesthetics like chloroform & ether stimulate the reflex

secretion of saliva . However , deep anaesthesia decrease the secretion due to central inhibition.

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Co relation between Saliva and Dental Caries

IgA

Carbonic acid-bicarbonate system

lact

ofer

rin

lysozyme

Lacto per oxidase

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Factors affecting flow of saliva

• Individual hydration• The Circadian and Circannual Cycle• Body Posture, Lighting, and Smoking• Medication• Thinking of Food and Visual Stimulation• Physical Exercise• Fasting and Nausea• Age• Gender• Alcohol

JADA NEWS ….(MAY,2008) 28

Saliva as Diagnostic Aid

SALIVA TESTS MAY REPLACE BLOOD TESTS

Patients may one day spit into a cup instead of undergoing

blood draws when being tested for the presence of cancer,

heart disease or diabetes..

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Advantages of using Saliva as a Diagnostic Specimen

• Non – invasive• Limited training• No special equipment• Potentially valuable for children• Cost effective• Eliminates the risk of infection• Easy, No pain and safest method• Screening of large population

No Pain

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Disadvantages• Samples are not sterile and subjected to bacterial

degradation• Difficult interpretation of salivary essays• Testing programme not yet available for saliva

Saliva in diagnostic technological assessment consist of 5 basic levels of analysis:

1) Analytic 2) Diagnostic3) Treatment efficacy4) Operational (response to treatment)

Saliva is used for diagnosis

Classified as• 1 ) Quantative analysis Hypo salivation -Sjogren’s syndrome - Drug induced Hyper salivation – Psychological Disturbance - Pregnancy - Parkinsonism - Nausea / vomitting

• 2.Qualitative analysis . Systemic diseases –Hereditary disease -Autoimmune -Malignancy -Infections Viral disease –HIV Drug monitoring Monitoring of hormone level

Hereditary diseases

• Cystic fibrosis elevated Ca and Phosphate in children leads to

increase in calculus formation.Raised PGE2

• Coeliac disease involes malabsorption of gluten. increase in salivary IgA-AGA

(Antiglaidin antibody)

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Autoimmune diseases• SJOGREN’S SYNDROME is a chronic autoimmune

disorder characterized by xerostomia (dry mouth), xerophthalmia (dry eyes), and lymphocytic infiltration of the exocrine glands

• Biopsies of minor salivary glands and predominant infiltration of inflammatory CD4 lymphocytes

• Sialochemistry and elevated levels of IgA, IgG, lactoferrin, and albumin, and a decreased concentration of phosphate were reported in saliva

Malignancy

BIOMARKER MALIGNANCY

p53 Squamous cell carcinoma

CA 125 Ovarian cancerc-erb B2 Breast cancer

The use of saliva as a predictable and a sensitive marker for the detection of either oral or systemic cancers appears to be a practical reality.

INFECTIONORGANISM DISEASE BIOMARKERStreptococcus mutans/lactobacillus species

caries Organisms (culture)

Porphyromonasgingivalis

Periodontal disease Organisms (culture)

Helicobacter pylori Peptic /duodenal ulcer

H.Pylori DNA (PCR)

ANTIGEN (pigeon) Pigeon breeder's disease

IgG antibodies

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HIV Infection

HIV antibody

Decreased IgA levels prognostic indicator

Orasure – saliva testing system

• Oral mucosal transudate –IgG antibodies

Other viral disease

• Hepatitis B- IgM• Hepatitis A- Virus RNA.• HSV1 toHSV8- Multiplex Polymerase Chain

Reaction

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Drugs

• Lithium, carbamazepine, barbiturates, benzo-diazepines, phenytoin, theophylline and cyclosporine can be detected in saliva

• High correlation between ethanol concentrations in saliva and in serum. The presence of thiocyanate in the saliva is an excellent indicator of active or passive smoking

Hormone monitoring

• Salivary steroid levels are in general good indicators of their blood concentrations.

• Consequently, the use of saliva for monitoring of steroid hormone levels is now feasible

• At present, the following steroid levels can be assessed using mixed saliva: cortisol, estradiol, estriol, progesterone and testosterone.

Hormone monitoring• Steroid hormone evaluation has been demonstrated

in a wide variety of situations ranging from assessment of;

• Child health and development• Mood and cognitive emotional behavior • Cushing’s syndrome• Ovarian function• Monitoring full-term and preterm neonates• Decreased salivary estriol was suggested as a marker

of fetal growth retardation

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Saliva/Oral Fluid Biomarkers Possibilities for Use

DNA Bacterial infectionDiagnosing carcinomas of the head &neckForensics

RNA Viral/bacterial identificationCarcinomas of the head and neck

Proteins Diagnosing periodontitisDetecting dental caries

Mucins/glycoproteins Diagnosing carcinomas of the head& neckDetecting dental caries

Immunoglobulins Diagnosing viruses (HIV, hepatitis B and C)

Viruses, bacteria Epstein-Barr virus reactivation (mononucleosis)

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1.HYPOSALIVATION The reduction in the secretion of saliva is called hyposalivation. 2

types :- Temporary - Permanent1) Temporary hyposalivation occurs in - emotional conditions like fear - fever - dehydration2) Permanent hyposalivation occurs in - sialolithiasis – obstruction of salivary duct - congenital absence or hypoplasia of salivary glands - bell’s palsy – paralysis of facial nerve

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Dry mouth (Xerostomia) –

• A loss of salivary function or a reduction in the volume of secreted saliva

• This occurs as a side effect of mediations taken by the patient for other problems.

• Symptoms – Oral dryness , loss of taste , difficulty in swallowing, decreased retention in denture.Signs – Fissured tongue , rampant caries , Candidiasis• Temporary relief is achieved by frequent sipping of water or artificial saliva .

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Management Dietary considerationsAvoid alcohol, smokingTake protein and vitamin supplements Preventive Dental Care Measures Mouth rinses.Antifungal medications. Saliva stimulants Oralbalance, XERO-Lube , Optimoist Saliva substitutesSugar free gum, lemon drops or mints – conservative methodsBiotine chewing gumPilocarpine HCl.

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2. HYPERSALIVATION The excess secretion of saliva is known as hypersalivation . Hypersalivation in

pathological condition is known as ptyalism or sialorrhea

Hypersalivation occurs in the following conditions :-

1) Decay of tooth or neoplasm of mouth or tongue due to continuous irritation of nerve endings in the mouth

2) Disease of esophagus , stomach & intestine3) Neurological disorder such as cerebral palsy & mental retardation4) Cerebral stroke5) Parkinsonism6) Some psychological & psychiatric conditions 7) Nausea & vomiting

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Drooling• Uncontrolled flow of saliva outside the mouth is called

drooling . It is often called ptyalism.• Etiology -Decreased Saliva swallowing and clearance, Excessive

Saliva production, Neuromuscular disease and Anatomic abnormalities

Management :

Non-specific Measures General measures to reduce Saliva Orthodontic appliances that aid swallowing Anticholinergic Medications

Specific Measures Treat Nausea Neuromuscular causes

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Saliva and Oral Health• Gingivitis: lack of saliva leads to retention of food particles in

the mouth, particularly interdentally and under dentures. This may result in gingivitis and in the long term, periodontitis.

• Oral ulceration: reduced saliva flow may result in recurrent aphthous ulceration, pain, lichen planus and secondary infection such as candidiasis. Antifungal rinses are used

•Mucositis: this is a painful condition where the mucous membrane of the oral cavity becomes ulcerated andinflamed. It can lead to dysphagia, dehydration and impaired nutrition.

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• Glossitis: with salivary hypofunction,the tongue can appear red, dry and raw, particularly on the dorsum, while the filiform papillae may be lost.

•Dentures: patients with hyposalivation often complain their dentures lose retention and stability. This can cause problems with speech, chewing, swallowing and nutritional intake.

It also increases the risk of candidal infections, ulceration, gingivitis, bacteraemia, viral infections and caries in the remaining teeth. Denture fixatives may be required to retain the removable prosthesis.Treatment is soft and hard tissue relines and denture adhesives

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• FREY'S SYNDROME/ GUSTATORY SWEATING also known as Auriculotemporal syndrome 

• is a food related syndrome which can be congenital or acquired specially after parotid surgery and can persist for life.

• The symptoms of Frey's syndrome are redness and sweating on the cheek area adjacent to the ear.

• They can appear when the affected person eats, sees, thinks about or talks about certain kinds of food which produce strong salivation.

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Saliva Collection Methods Draining / Spitting Method : The

subject is asked to accumulate saliva in the floor of the mouth and then spit into a graduated test tube

Suction Method:a plastic saliva ejector tip connected to a vacuum pump is placed under the tongue. The saliva is led by a plastic tube into a test tube. At the end of collection, the ejector is moved around in the mouth to collect the remaining saliva

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• Stimulated saliva-collected by masticatory action (from a subject chewing on paraffin) or by gustatory stimulation (application of citric acid on the subject's tongue)

• Unstimulated salivary flow rate is most affected by the degree of hydration, exposure to light, body positioning, and seasonal and diurnal factors

Swab Method: 3 preweighed cotton rolls are placed in the mouth , one

below the tongue and two on either side in the buccal vestibule.

At the end of collection time cotton rolls are removed and weighed.

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Conclusion• Saliva has an important role in patient’s quality of life. Dental

professionals need to be aware of the problems that arise when there is an overproduction or underproduction of saliva, and also a change in its quality.

• Checking the patient’s medical history regularly can identify conditions or medications that can adversely influence saliva production.

• Understanding the role of saliva in maintaing health , as well as its relation to oral diseases is vital for dentist

• What water is to desert , saliva is to the oral cavity.

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References• Tencate’s oral histology- 8TH Edition• Textbook of medical physiology- guyton 9th edition• Textbook of Oral Pathology- Shafer,Hine & Levy• Carranza’s clinical periodontology- 10 th edition• de Almeida Pdel V, Grégio AM, Machado MA, de Lima AA,

Azevedo LR. Saliva composition and functions: a comprehensive review. J Contemp Dent Pract. 2008 Mar 1;9(3):72-80

• Puy CL. The rôle of saliva in maintaining oral health and as an aid to diagnosis. Med Oral Patol Oral Cir Bucal 2006;11:E449-55

• Gupta P, Dahiya P, Bansal S, Gupta R. Saliva A Revolutionary Approach In Diagnosis. Indian Journal of Dental Sciences 2012;4(3)44-46

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Thank You