saliva final.pptx

Saliva

1. SALIVA By: KHYATI ARORA MDS 1 ST YEAR

2. CONTENTS INTRODUCTION EMBRYOLOGY CLASSIFICATION OF SALIVARY GLANDS MECHANISM OF FORMATION OF SALIVA COMPOSITION FUNCTIONS OF SALIVA CONTROL OF SALIVATION FACTORS AFFECTING COMPOSITION AND SECRETION OF SALIVA CO-RELATION BETWEEN SALIVA AND DENTAL CARIES

3. 10. ROLE OF SALIVA IN ACQUIRED PELLICLE FORMATION 11. ROLE OF SALIVA IN CALCULUS FORMATION 12. ROLE OF SALIVA IN SALIVARY GLAND DISEASE 13. METHODS OF SALIVA COLLECTION 14. SALIVARY MARKERS IN PERIODONTAL DISEASE 15. CLINICAL CONSIDERATIONS OF SALIVA 16. DISEASES OF SALIVARY GLANDS 17. CONCLUSION 18. REFERENCES

4. INTRODUCTION Saliva lacks the drama of blood, the emotion of tears and toil of sweat but it still remains one of the most important fluids in the human body. Its status in the oral cavity is at par with that of blood i.e. to remove waste, supply nutrients & protect the cells. first digestive juice that comes in contact with food.

5. It helps in the process of food digestion, taste, lubrication, formation of food bolus and neutralization of acids with in the oral cavity. Saliva is one of the major natural defence systems of the oral cavity . 5

6. DEFINITION Saliva is a clear, tasteless, odorless, slightly acidic, viscous fluid consisting of secretions from the parotid, Submandibular & mucous glands of oral cavity. Stedman’s Medical Dictionary Saliva is a clear, alkaline, somewhat viscous secretion from the parotid, submandibular , sublingual & smaller mucous glands of the mouth. Dorland’s Medical Dictionary

7. The secretions of the major and minor salivary glands together with the gingival crevicular fluid, constitute the oral fluid or whole saliva , which provides the chemical milieu of the teeth and oral soft tissues . ( Neubrun ) 7 MAJOR GLANDS SALIVA MINOR GLANDS GCF GCF

8. EMBRYOLOGY OF SALIVARY GLANDS Salivary glands develop as outgrowths of the buccal epithelium. The outgrowths are at first solid and later canalized They branch repeatedly to form the duct system The terminal parts of the duct system develop into secretory acini. As the glands develop near the junctional area between the ectoderm of the stomatodaeum and the endoderm of the foregut,it is difficult to determine if they are ectodermal or endodermal.

9. The outgrowth for the parotid gland arises in relation to the line along which the maxillary and mandibular processes fuse to form the cheek. It is generally considered to be ectodermal . The outgrowths for the submandibular and sublingual arise in relation to the linguo-gingival sulcus. They are usually considered to be of endodermal origin.

10. CLASSIFICATION OF SALIVARY GLANDS (a)According to size and location

11. PAROTID GLAND Largest of all the salivary glands Purely serous gland Superficial portion lies in front of the external ear and deeper portion lies behind the ramus of the mandible Stensons duct  Opens out adjacent to maxillary second molar Stenson’s duct arises from the anterior border of the Parotid and parallels the Zygomatic arch, 1.5 cm inferior to the inferior margin of the arch.

12. SUBMANDIBULAR GLAND Second largest salivary gland Produces 65-70% of total saliva output The duct is called Wharton’s duct Wharton’s duct exits on the floor of the mouth opposing the lingual surface of the tongue Innervated by parasympathetic nerve endings Mixed secretion – mostly serous

13. SUBLINGUAL SALIVARY GLAND Smallest of the major glands Produce less than 5% of total saliva output Saliva delivered via the ducts of Bartholin The Bartholin ducts exit on the base of the lingual surface of the tongue Innervated by parasympathetic fibers Little or no sympathetic influence Mixed secretion – mostly mucous

14. (B) ACCORDING TO THE HISTOCHEMICAL NATURE OF SECRETORY PRODUCTS

15. FORMATION OF SALIVA 15

16. COMPOSITION OF SALIVA Organic -60% Inorganic-40% Water : 99.5% 16

17. ORGANIC CONSTITUENTS GLYCOPROTEINS Secretion of parotid gland: watery in nature contains cationic glycoproteins of low molecular weight . Submandibular and sublingual gland secretions: sticky and viscous contains high molecular weight glycoproteins which are anionic in nature. 17

18. ENZYMES: Amylase(ptyalin ):catalyse starch into sugar Lysozyme :It is a hydrolytic enzyme that cleavages the linkage between structural components of the glycopeptide muramic acid containing – cell walls of certain bacteria in vitro It works both on gram + ve and gram – ve organisms mainly include Veillonella species and Actinobacillus actinomycetemcomitins It probably repels certain transient bacterial invaders of mouth 18

19. Peroxidase : Myeloperoxidase , an enzyme similar to salivary peroxidase is released by leukocytes and is bactericidal for Actinobacillus has added effect of inhibiting the attachment of Actinomyces strain to hydroxyapatite Lactoperoxidase -thiocyanate : bactericidal to Lactobacillus and Streptococcus By preventing the accumulation of lysine and glutamic acid

20. Proteases, amino-peptidase, carboxypeptidases ,urease Lipase :break down dietary fats into fatty acids and glycerol Lactoferrin : capable of antibacterial activity by direct binding of bacteria to lactoferrin and agglutinating S.mutans thus, allowing easy removal of agglutinated bacteria via mechanical action of saliva

21. COAGULATION FACTORS Saliva also contains coagulation factors VIII, X, XI, plasma thromboplastin antecedent (PTA) and the Hageman factor that hasten blood coagulation and protect the wounds from bacterial invasion

22. HORMONES : Parotin , Nerve growth factor, Gustin VITAMINS : Thiamine, Riboflavin, Niacin, Pyridoxine, Folic acid, Vitamin C, Vitamin B12, Vitamin K 22

23. CARBOHYDRATES Has glucose at a concentration of 0.5-1mg/100ml (parotid) In submandibular – glucose, hexose, fructose with small amounts of hexosamine and sialic acid

24. LIPIDS Small amount of diglycerides, triglycerides, cholesterol and cholesterol esters, phospholipids, corticosteroids. Play a role in salivary protein binding ,bacterial adsorption to apatite, and plaque microbial aggregation . 24

25. IMMUNOGLOBULIN OR SALIVARY ANTIBODIES 25 IgG, IgA, IgM are present Saliva, like GCF, contains antibodies that are reactive with indigenous oral bacterial species. IgG is more prevalent in GCF Major and minor salivary glands contribute all of the secretory IgA (sIgA) and lesser amounts of IgG and IgM.

26. IgA: main specific immune defense mechanism in saliva important in maintaining homeostasis in the oral cavity IgG is primarily derived from serum via GCF and is present in low concentration. IgG concentration increase in saliva during inflammation of the periodontal tissue which causes more severe vascular permeability.

27. MUCOUS It lubricates and protect both soft and hard tissues of oral cavity

28. INORGANIC COMPONENTS Sodium - 2-21 mmoI /L Potassium – 10-36 mmol /L Calcium – 1.2-2.8 mmol /L Magnesium – 0.08-0.5 mmol /L Chloride – 5-40mmol/L Bicarbonate – 25mmol/L Hydrogen phosphate – 1.4-3.9mmol/L Fluoride - <1m/Mol/L 28

29. 1-SODIUM Contributes to osmolarity of saliva( osmolarity is ½-3/4 th of blood). gives diagnostic information relating to the efficiency of ductal transport system. 2-CALCIUM saliva is supesaturated with calcium and hence prevents dissolution of enamel. facilitates enamel mineralization.

30. 3-POTASSIUM Contributes to osmolarity of saliva. reaches saliva by active processes in both acini and ducts. Concentration falls immediately after stimulation and then approximately constant.

31. 4- BIOCARBONATE Most important buffer in saliva [resist change in salivary Ph when acid or alkali added]. Biocarbonates release weak carbonic acid when acid is added ; this is rapidly decomposed to H2O and CO2 which leaves the solution resulting in complete removal of acids 5- CHLORINE Contributes to osmolarity of saliva. Increased flow rate leads to increased chloride reabsorption .

32. 6- FLUORIDE fluoride is well known for its anti-caries property. peak concentration of fluoride in gland saliva are observed some 30-60 minutes after ingestion of fluoride dose. 7- PHOSPHORUS it is actively transported into saliva , probably mainly in the acini but possibly also in the ducts 32

33. PROPERTIES OF SALIVA Daily secretion : 700-1500ml / 24hrs Normal flow rate Unstimulated : 0.2-0.3 ml/min Stimulated : 1 – 2 ml/min Consistency : cloudy, colorless , opalescent fluid pH: 6.7 – 7.4 Specific gravity : 1.002 -1.012 33

34. Freezing point : 0.07°C - 0.34°C Volume of secretion : Parotid gland :20% submandibular gland :65% sublingual gland:5% Viscosity : Parotid gland :1.5 submandibular gland :3.4 sublingual gland:13.4 34

35. FUNCTIONS OF SALIVA LUBRICATION Saliva provides a tissue coating film which is responsible for lubrication and bolus formation. Important for mastication and swallowing and for general oral health and comfort.

36. CLEANSING ACTION A constant flow of saliva has a cleansing effect on the mouth & teeth and helps in oral hygiene and prevents dental caries. WATER BALANCE Dryness of the mouth evokes the sensation of thirst in times of dehydration. Thus salivation plays a role in the maintenance of water balance of the body.

37. DIGESTION Salivary amylase initiates the digestion of starch. Later inactivated in the stomach because of low pH and proteolytic acid. NEUTRALIZATION AND BUFFERING Saliva is alkaline and is an effective buffer system. These properties protect the oral tissues against acids from food or from plaque

38. FACILITATION OF SPEECH activation of words is not clear when mouth is dry s aliva lubricates the oral cavity for proper activation of speech STARCH DIGESTION only digestive function of saliva is due to ptyalin, which is a weak amylolytic enzyme. It acts on the starch and converts it into maltose. The optimum pH necessary for this action is 6.8. The intermediate products involved are dextrin, erythrodextrin and Achrodextrin

39. EXCRETORY FUNCTION Helps in excreting certain heavy metals like lead and iodine etc. ANTI BACTERIAL EFFECTS Immunoglobulins: Salivary antibodies are mainly of IgA class - to aggregate specific bacteria and prevent their adhesion to oral hard and soft tissues.

40. CONTROL OF SALIVATION Salivary glands are under the control of autonomic nervous system and receive efferent nerve fibres from both parasympathetic and sympathetic divisions of autonomic nervous system.

41. Parasympathetic fibres to submandibular and sublingual glands

42. Parasympathetic fibres to parotid gland

43. FACTORS INFLUENCING THE COMPOSITION & SECRETION OF SALIVA Flow rate : - Spontaneous(asleep): for 8 hrs at the rate of 0.05 ml / min - Unstimulated/ Resting Saliva : 12 hrs at 0.7 ml / min -Stimulated: 4 hrs at 2.0 ml / min 43

44. Substances whose concentration increases as the flow rate increases : total protein amylase, sodium bicarbonate. Substances whose concentration decreases as the flow rate increases : phosphate, urea, amino acid, uric acid, serum albumin Substances whose concentration does not change with change in flow rate: fluoride

45. FACTORS AFFECTING FLOW RATE DIURINAL VARIATION : Salivary flow exhibits diurinal variation Calcium high in the night

46. 2. DURATION OF SALIVATION : If salivary gland are stimulated for more than 3 min , the conc of the components in saliva is reduced. 3. DIET: -Fluoride content may increase in children drinking fluoridated water. - Diet rich in protein increase blood urea level thus increase urea conc in saliva. 46

47. 4. DIETARY FACTORS: -functional salivary glandular activity is influenced by mechanical and gustatory factors e.g., copious salivary flow results from the smell of food or new denture insertion 5. PLASMA COMPOSITION: - increase in plasma aldosterone concentration lower the Na and increases K conc.in saliva. 47

48. IM PORTANT SALIVARY FACTORS AFFECTING MINERALIZATION Calcium and phosphate :- Saliva is rich in calcium and phosphate thus facilitating remineralization of early carious lesion. 2) Salivary pH and Buffering capacity :- Buffering capacity of saliva is also an important factor for protection against dental caries. 48

49. 3) Statherin :- Acidic peptide that contains high levels of proline , tyrosin and phosphoserine . It inhibits spontaneous precipitation of calcium phosphate salts from supersaturated saliva and favours remineralization . 49

50. 4 ) Histatines :- Group of histidine rich proteins. Major form in oral cavity are histatin 1,histatin 3, and histatin 5. Antibacterial effect against S mutans in oral cavity. Most important role played by histatin is to bind to hydroxyapatite and prevent calcium phosphate precipitation from a supersaturated saliva which favours remineralization . 50

51. 5) Proline-rich Proteins (PRPs):- Inhibitors of calcium phosphate crystal growth Present in the initially formed enamel pellicle and in “ mature ” pellicles

52. 6) Cystatins:- Are inhibitors of cysteine -proteases Protective against unwanted proteolysis (bacterial proteases, lysed leukocytes) Inhibit proteases in periodontal tissues 52

53. 7) Fluoride :- It has an antibacterial effect. It plays an important role in remineralization . 53

54. 8) Mucins :- Lubrication Glycoproteins - protein core with many oligosaccharide side chains attached by O-glycosidic bond More than 40% of carbohydrates Hydrophillic , entraining water (resists dehydration) Unique rheological properties (e.g., high elasticity, adhesiveness, and low solubility) Two major mucins (MG1 and MG2)

55. CO-RELATION BETWEEN SALIVA AND DENTAL CARIES It is capable of regulating the pH of the oral cavity by the help of its bicarbonate content as well as its phosphate and amphoteric protein constituents. Increase in secretion rate usually results in an increase in pH and buffering capacity.

56. Because of its calcium and phosphate content, it helps to maintain the integrity of teeth. Tooth dissolution is prevented or retarded and re-mineralization is enhanced by the presence of copious salivary flow. 56

57. The flow of saliva can reduce plaque accumulation on the tooth surface. The diffusion into plaque of salivary components such as calcium, phosphate, hydroxyl and fluoride ions enhances re-mineralization of early carious lesions.

58. Lysozyme, lactoperoxidase and lactoferrin in saliva have a direct antibacterial action on plaque. Salivary proteins could increase the thickness of the acquired pellicle and so help to retard the movement of calcium and phosphate ions out of enamel. lactoferrin lysozyme lactoperoxidase

59. ROLE OF SALIVA IN ACQUIRED PELLICLE FORMATION Most of the organic and inorganic constituents of supra gingival plaque are derived from saliva. Glycoproteins form the important component of pellicle that initially coats the tooth surface. The inorganic components of supra gingival plaque such as calcium, phosphorous and trace elements like sodium, potassium & fluoride are derived from saliva.

60. The hydroxyapatite surface has a predominance of negatively charged phosphate group that binds with positively charged particles in saliva. These glycoproteins bind with plaque forming bacteria. Glycoprotein bacterial interactions result in bacterial accumulations on the exposed tooth surface. Glycoproteins also aid in the maintenance of integrity of dental plaque.

61. ROLE OF SALIVA IN CALCULUS FORMATION As the mineral content in the plaque mass increases it gets calcified to form calculus. It is usually found in the areas of dentition adjacent to salivary ducts. (lingual surface of mandibular anterior &buccal surface of maxillary posteriors) reflecting high conc of minerals available from saliva in those areas.

62. Salivary proteins account for 5.9% to 8.2% of the organic content of supra gingival calculus. Various proteins derived from saliva are glucose, galactose, glucuronic acid, galactosamine Plaque has the ability to concentrate calcium 2 – 20 times its level in saliva. A raise in the Ph of saliva causes precipitation of calcium phosphate salts by lowering the precipitation constant.

63. METHODS OF SALIVA COLLECTION

64. SALIVARY BIOMARKERS IN PERIODONTAL DISEASE Increased concentrations in periodontal disease: Hyaluronidase, Lipase, B-glucuronidase, chondroitin sulfatase, aspartate amino- transferase, alkaline phosphatase, amino acid decarboxylases, catalase, peroxidases, and collagenase

65. Proteolytic enzymes: initiation and progression of diasease saliva secrete Antiproteases- inhibit cysteine proteases such as cathepsains Antileukoproteases - inhibit elastase Leukocytes, mainly PMNs- increases in gingivitis Living PMNs- orogranulocytes Rate of migration in oral cavity: orogranulocytic index Reliable for the assessment of gingivitis

66. CLINICAL CONSIDERATIONS OF SALIVA 1. HYPOSALIVATION The reduction in the secretion of saliva is called hyposalivation . It is of two types , namely 1) Temporary hyposalivation occurs in i ) emotional conditions like fear ii) fever iii) dehydration 2) Permanent hyposalivation occurs in - sialolithiasis – obstruction of salivaary duct - congenital absence or hypoplasia of salivary glands - bell’s palsy – paralysis of facial nerve

67. 2.DRY MOUTH (XEROSTOMIA) It is a frequent clinical complaint loss of salivary function or a reduction in the volume of secreted saliva may lead to the sensation of oral dryness. occurs as a side effect of mediations taken by the patient for other problems. Many drug cause central or peripheral inhibition off salivary secretion. Loss of gland function occurs after radiation therapy for head and neck cancer

68. TREATMENT (SIALOGOGUES) Oral Spray Oasis : 1-2 sprays NOT TO EXCEED 60 SPRAYS/DAY Aquoral 2 SPRAYS TID Oral Solution Caphosol : packaged in two 15 mL ampules when mixed together provide one 30 mL dose SWISH AND SPIT; NOT TO EXCEED 10 DOSES/DAY

69. Lozenge- Saliva Sure DISSOLVE IN MOUTH, NOT TO EXCEED 16 LOZENGES/ DAY Adhering disc- XyliMelts APPLY 2 DISCS BEFORE BED, 1 ON EACH SIDE OF THE MOUTH SWALLOW AS IT SLOWLY DISSOLVES

70. ANTISIALOGOGUES Reduces the salivary secretion APPLICATIONS: surgeries of salivary glands and ducts intra-oral procedures gingival retraction sialocele reduction and salivary gland healing E.g., Atropine, anticancer drugs, antihistaminincs

71. 3) SJOGREN’S SYNDROME chronic autoimmune disorder characterized by xerostomia (dry mouth), xerophthalmia (dry eyes), and lymphocytic infiltration of the exocrine glands. This triad is also known as the sicca complex . autoimmune disorder in which the immune cells destroy exocrine glands such as lacrimal glands & sweat glands .

72. named after HENRIK SJOGREN causes dryness of skin , nose. severe condition the organs like kidneys ,lungs, liver , pancreas , thyroid , blood vessels & brain are affected

73. 4) AGE CHANGES With age a generalized loss of gland parenchymal tissue occurs. The lost salivary cells often are replaced by adipose tissue 5) CARIES a major problem of a reduced salivary flow saliva normally washes away acids. There may be an increase in recurrent decay on coronal as well as root surfaces. Incisal edges of Anterior teeth may also develop carious lesions as well as recurrent lesions on the margins of restorations.

74. 6) DENTAL EROSION Low buffering capacity and flow rate indicate a greater erosion risk and advice should be given to the patient to minimise this. This should include following acidic intake with a glass of water to aid clearance and finishing each meal with a neutral salivary stimulant, such as cheese, to promote salivary flow. Chewing sugar-free gum also stimulates production of saliva.

75. 7)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 8) ORAL ULCERATION reduced saliva flow may result in recurrent aphthous ulceration, pain, lichen planus, delayed wound healing and secondary infection, such as candidiasis.

76. 10) HALITOSIS Saliva gives rise to bad odours especially during mouth breathing prolonged talking or hunger Eating reduces halitosis partly because it increases saliva flow and friction in the mouth. 9) MUCOSITIS painful condition where the mucous membrane of the oral cavity becomes ulcerated and inflamed It increases susceptibility to fungal infections such as candidiasis. lead to dysphagia, dehydration and impaired nutrition.

77. 11) HYPERSALIVATION excess secretion of saliva Hypersalivation in pathological condition is known as ptyalism , sialorrhea , sialism or sialosis . Occurs in:- Decay of tooth or neoplasm of mouth or tongue due to continuous irritation of nerve endings in the mouth Disease of esophagus , stomach & intestine Neurological disorder such as cerebral palsy & mental retardation

78. 12) DROOLING Uncontrolled flow of saliva outside the mouth often called ptyalism. occurs because of excess production of saliva in association with inability to retain saliva within the mouth. Drooling in small children is a normal part of development.  Teeth are coming in, they put everything in their little mouths, and they haven’t developed the habit of keeping the lips together .

79. 13) CHORDA TYMPANI SYNDROME characterized by sweating while eating During the regeneration of the nerve fibers following trauma or surgical division, which pass through chorda tympani branch of facial nerve may deviate & join with the nerve fibers supplying sweat glands

80. 14)FREY'S SYNDROME or GUSTATORY SWEATING Baillarger’s syndrome , Dupuy’s syndrome ,  Auriculotemporal syndrome  or  Frey- Baillarger syndrome ) food  related  syndrome  which can be congenital or acquired specially after parotid surgery; persist for life. Symptoms: 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 .

81. 15)PARALYTIC SECRETION OF SALIVA when the parasympathetic nerve to salivary gland is cut , salivary secretion increases for the first 3 weeks & later diminishes finally it stops at about 6th week The increased secretion of saliva after cutting the parasympathetic nerve fibers is called paralytic secretion

82. 16)AUGMENTED SECRETION OF SALIVA if the nerve supplying salivary glands are stimulated twice , the amount of saliva secreted by the second stimulus is more than the amount secreted due to the first stimulus. because , the first stimulus increases excitability of acinar cells , so that when the second stimulus is applied , the salivary secretion is augmented .

83. EFFECT OF DRUGS & CHEMICAL ON SALIVARY SECRETION Sympathomimetic drugs like adrenaline & ephedrine stimulates salivary secretion Parasympthomimetic drugs like acetylcholine , pilocarpine , muscarine & physostigmine increase the salivary secretion Histamine stimulates the secretion of saliva

84. 4) Parasympathetic depressants like atropine inhibit the secretion of saliva 5) Anaesthetics like chloroform & ether stimulate the reflex secretion of saliva However , deep anaesthesia decrease the secretion due to central inhibition.

85. DISEASES OF SALIVARY GLANDS DEVELOPMENTAL ANOMALIES : Aberrant salivary glands Aplasia and hypoplasia Accessory ducts SIALOLITHIASIS MUCOCELE NECROTIZING SIALOMETAPLASIA INFLAMMATORY DISORDERS

86. VIRAL INFECTIONS: Mumps Cytomegalovirus infection HIV associated salivary gland disease BACTERIAL INFECTIONS : Acute bacterial sialadenitis Chronic bacterial sialadenitis Allergic sialadenitis Sarcoid sialadenitis Sialadenosis SJOGREN’S SYNDROME

87. SIALOLITHIASIS formation or presence of a calculus or calculi in a salivary gland most commonly seen in the submandibular gland and duct (about 80% of cases) rare in the sublingual gland. Most stones are solitary, but multiple stones may be present. Symptoms: May be asymptomatic, Dull pain from time to time over the affected gland, swelling of the gland and Pain with chewing or swallowing Complications: Oral infection

88. SIALADENITIS flow is reduced or stopped for some reason, infection can grow, called sialadenitis. most common infection: bacterial common in the parotid gland and the submandibular gland Symptoms: Tender, painful lump in cheek or under chin, Pus may drain through the gland into the mouth. If the infection spreads, fever, chills and malaise may occur. Complications : Oral infection, Upper respiratory tract infection, Upper GIT infection

89. CONCLUSION Saliva is a complex secretion that plays a major role in general and oral health and disease It lubricates and protects the structures of the mouth and influence the nature of oral microbial flora and even the chemical composition of teeth Saliva plays an important role in formation of calculus and plaque and is there intimately related to caries and periodontal disease

90. REFERENCES Human physiology BY AK Jain Human Anatomy By BD Chaurasia Carranza Clinical Periodontology 11 th edition Oral Histology & Embryology- Orban’s 10 th edition