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  1. 1. Presented By: Dr. Rupali Das II year PG Dept Of Periodontics 25-4-12
  2. 2. CONTENTS 1. Introduction 2. Composition of saliva 3. Functions of saliva 4. Salivary glands a) Morphologic characteristics of Salivary glands b) Formation & secretion of saliva c) Ductal modification of saliva d) Development of salivary glands e) Blood supply & nerve supply 5. Collection of saliva 6. Physical properties of saliva 7. Flow rate 6. Factors affecting the salivary flow rate 7. Clinical Aspects a) Salivary gland hypofunction & hypersalivation b) Role of saliva in periodontal pathology c) Saliva as a diagnostic marker 8. Conclusion 9. References
  3. 3. INTRODUCTION • Is a clear, slightly acidic,mucoserous secretion,which provides chemical milieu of the teeth and oral soft tissue. • Saliva is composed of more than 99% water and less than 1% solids , mostly electrolytes and proteins, the latter giving saliva its characteristic viscosity. • Normally the daily production of whole saliva ranges from 0.5 to 1.0 litres
  4. 4. CLASSIFICATION 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
  5. 5. 3. Based on type of secretion – Serous – Mucous – Mixed Parotid glands - Purely serous Submandibular-Predominantly serous, Mixed Sublingual - Predominantly mucous , Mixed Labial,Buccal,Lingual{Ant.}- Mucous , Mixed Palatine,Glossopalatine - Purely mucous. Posterior part of the tongue - Purely mucous Von Ebner’s Glands - Purely serous
  7. 7. • 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
  8. 8. Anti bacterial substances Lysosyme Lactoferrin Sialoperoxidase Glycoproteins Proline rich glycoprotein seen in parotid saliva. Other compounds Siatherin Sialin Free amino acids Urea Glucose
  9. 9. • Inorganic constituents Sodium Potassium Chloride Bicarbonate Calcium Phosphorus Flouride Thiocyanate
  10. 10. FUNCTIONS
  11. 11. Functions of Saliva Components Mucins Lubricate food Protect teeth against acid Help protect against bacteria, viruses, fungi Digestive Enzymes α-Amylase – digests starches Lipase – digests fats Protease – digests proteins Lysozyme Peroxidases Lactoferrin Histatins Cystatins Anti-bacterial agents Secretory Immunoglobulin A Histatins Cystatins Anti-fungal, anti-viral agents
  12. 12. Bicarbonate ions Phosphate ions Proteins Help protect teeth and soft tissues against acidic conditions Calcium ions Phosphate ions Proline-rich proteins Help maintain mineral content of tooth enamel
  13. 13. PROPERTIES OF SALIVA • Consistency : Slightly cloudy • Reaction : Usually slightly acidic • PH : 5-8 • Specific gravity : 1.0024 – 1.0061 • Freezing point :0.07 – 0.34 degree Celsius • Osmotic pressure : ( 700-1000m osmol/litre )
  14. 14. The Salivary Glands Human saliva is produced by 3 Major salivary glands, The Parotid, the Submandibular,the Sublingual, as well as numerous minor salivary glands.
  15. 15. Time of origin Gland Location Intra uterine life Parotid gland Corners of the stomodeum 6th week Sub.Mand.gland Floor of the mouth End of 6th week Sub.Ling.gland Lateral to S.m.primordium 8th week Minor salivary Buccal Epithelium 2nd week Glands
  16. 16. STAGES OF DEVELOPMENT • STAGE I-Bud formation: Induction of proliferation of oral epithelium by underlying mesenchyme.
  17. 17. • STAGE II:Formation and growth of epithelial cord.
  18. 18. • STAGE III: Initiation of branching in terminal parts of epithelial cord and continuation of glandular differentiation.
  19. 19. • STAGEIV: Dichotomous branching of epithelial cord and lobule formation.
  20. 20. • STAGE V:Canalization of presumptive ducts.
  21. 21. STAGE VI: Cytodifferentiation. Cells of  Terminal tubule cell  Proacinar cellsAcinar cells Bulb region  Intercalated duct cell
  22. 22. • Septa ( Thicker partitions of the connective tissue ) which are continuous with the connective tissue capsule surrounding the gland parenchyma into lobes & lobules & carry the blood vessels & nerves that supply the parenchymal components & the excretoryducts. Secretory end pieces & ducts - last 2 months of gestation. The glands continue to grow postnatally upto 2 years of age.
  24. 24. 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.
  25. 25. 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
  26. 26. • 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)
  27. 27. The minor salivary glands: 1.Estimated numbers is 600-1000. 2.Exist as small,discrete,aggregates of secretory tissue present in the submucosa through out 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.
  28. 28. 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
  29. 29. INFLUENCE OF BLOOD SUPPLY ON SALIVARY SECRETION  Extensive blood supply is required for rapid salivary secretion.  Salivation indirectly dilates blood vessels providing increased nutrition.  Large increase in blood flow accompanies salivary secretion.
  30. 30. 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
  31. 31. 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
  32. 32. 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, and myoepithelial cells.
  33. 33. • Intercalated duct : main duct connecting acinar secretions to rest of the gland, not involved in modification of electrolytes • Striated duct: electrolyte regulation in resorbing sodium • Excretory duct: continuing sodium resorption and secreting potassium • 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.
  34. 34. Secretory cells: There are two types of secretory cells. 1.serous cells 2.mucous cells
  35. 35. 1.SEROUS CELLS: a) These are spherical, consisting of 8-12 cells surrounding a central lumen. b) Cells are pyramidal with a broad base & narrow apex c) The lumen usually has finger like extensions located between adjacent cells called inter cellular canaliculi. d) Spherical nuclei are located basally, occasionally binucleated cells are seen.
  36. 36. e) Secretory granules are present in the apical cytoplasm. f) These cells are joined by intercellular junctions. a.Zonula occludens( tight junction) b.Zonula adherens(Adhering junction) c.Macula adherens(desmosome) These cells are attached to the basal lamina & the underlying connective tissue by hemidesmosomes.
  37. 37. 2.MUCOUS ACINI: a) These have a tubular configuration. b) In cross section, they appear as round profiles with mucous cells surrounding a central lumen of larger size than that of serous end pieces c) Mucous end pieces have serous cells associated with them in the form of a demilune or cresent covering the mucous cells at the end of the tubule.
  38. 38. d) The most prominent feature -accumulation of large amounts of secretory product (mucus) in the apical cytoplasm, which compresses the nucleus & endoplasmic reticulum & golgi complex against the basal cell membrane. e) Unlike serous cells, however, mucous cells lack intercellular canaliculi, except for those covered by demilune cells.
  39. 39. MYOEPITHELIAL CELLS: a) These are basket shaped cells b) Cntractile in nature. b) Located between the basal lamina & the secretory/duct cells & are joined to the cells by desmosomes. c) Similar to the smooth muscle cells but are derived from the epithelium.
  40. 40. e) Help to expel the primary saliva from the endpiece into the duct system. f) Provide signals to the acinar secretory cells for maintaining cell polarity & structural organization of the secretory end piece. g) Produce a no. of proteins that have tumour suppressor activity, such as proteinase inhibitors ( ex : tissue inhibitor of metalloproteinases ) & antiangiogenesis factors h) Provide a barrier against invasive epithelial neoplasms.
  41. 41. 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.
  42. 42. Salivary Gland Secretions Gland type Saliva type Parotid, and Von Ebner’s (on the tongue) Serous Submandibular Mixed, more serous than mucous Sublingual Mixed, but mostly mucous Most minor Mucous
  43. 43. WHOLE SALIVA
  44. 44. COLLECTION OF SALIVA • Non invasive, non painful techniques exist to collect whole saliva, as well as saliva from the individual major & minor salivary glands . • Whole saliva is easily obtained & is in most case a good indicator of whole mouth dryness. • Diseases of salivary gland can often be diagnosed from the secretions obtained directly. • The quantification of salivary output is referred to as sialometry.
  45. 45. 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
  46. 46. Collection Of Stimulated Saliva • Paraffin method (Masticatory stimulus ) • Citric Acid method ( Gustatory Stimulus )
  47. 47. Collection Of Unstimulated Saliva
  48. 48. SALIVARY FLOW RATE • Salivary flow varies in the stimulated (eg, chewing) and unstimulated state. • Stimulated flow - – 90% of average daily saliva production – At a rate of between 0.2 and 7 mL/min – Parotid glands contribute > 50% of total salivary flow. • Unstimulated state – – Normal flow > 0.1 mL/min – Submandibular glands - 65% of total flow; – Parotid glands - 20% – Sublingual glands - 7%–8%.
  49. 49. Factors affecting salivary flow rate Diurnal variation: • Protein concentrations tend to be high in the afternoon. • Sodium & chloride concentrations are high in the morning, while potassium is high in the early afternoon. • The calcium concentration increase at night. Duration of stimulus: • If the salivary glands are stimulated for long than 3 minutes, the concentration of many components is reduced. • Chloride concentrations fall during periods of stimulation.
  50. 50. Hormonal Influences • Aldosterone: It results in increased sodium reabsorption in the striated ducts. • Antidiuretic hormone (ADH): Stimulates water reabsorption by the striated duct cells. • Other hormones: Thyroxine results in increase salivary secretion • Local hormones: Bradykinin & its predecessor kallidin, result in increased salivary secretion.
  51. 51. CONDITIONS AFFECTING SALIVATION Physiologic •Taste • Surface texture •Dehydration • Age •Mastication • Emotion Pathologic conditions •GI irritants • Ill fitting dentures/inadequate interocclusal distance •Vitamin deficiency •Trauma from surgery • Senile atrophy of the salivary glands • Irradiation therapy • Dieseases of the brain stem • Diabetes mellitus/ insipidus • Diarrhoea • Acute infectious diseases Drugs • Cholinesterase inhibitors- Prostigmine • Adrenergic stimulating drugs-epinephrine • Sialogogues- pilocarpine. • Antihistamines - Atropine •Drugs for peptic ulcer – Omeprazole, Ranitidine. •Antihypertensives – Captopril. •Antiparkinsonian drugs – Levodopa. •Antianxiety agents- Benzodiazepines. •Antidepressants – Olanzepine. •Diuretics – Furesemide.
  52. 52. ANOMALIES I.Developmental Aberrant Salivary Glands Aplasia and Hyperplasia Atresia II.Obstructive conditions Sialolithiasis Mucocele Necrotizing Sialometaplasia III. Inflammatory Diseases Viral- Mumps , H.I.V. Associated Bacterial - Sialadenitis
  53. 53. IV.Neoplastic Diseases Benign Malignant V.Degenerative Conditions Sjogren’s Syndrome Ionizing Radiation VI.Xerostomia
  54. 54. XEROSTOMIA Systemic diseases 1. Rheumatoid conditions Collagen/vascular, connective tissue diseases, ex: • It is a condition of reduced or absent salivary flow,leading to the dryness of the mouth. Sjogren’s syndrome 2.Dysfunction of the immune system AIDS • It is not a disease by itself, but a symptom associated with alterations 3. Hormonal Disorders Diabetes mellitus of salivary function. 4. Neurological disorders Parkinson’s disease • The principal causes of salivary gland hypofunction & xerostomia 5. Dehydration Therapeutic irradiation External beam, whole- body,131I Drugs / medications Anticholenergics,Antidepressants,Antihypertensive Antipsychotics,& Antiparkinsonism drugs Psychogenic Disorders Depression Surgical removal of the glands
  55. 55. Oral symptoms Clinical signs 1. Dry mouth ( xerostomia ) 2. Often thirsty 3.Dysphagia (difficulty with swallowing ) 4. Dysphonia ( difficulty with speaking ) 5. Dysgeusia ( abnormal taste sensation ) 6. Difficulty with eating dry foods 7. Need to frequently sip water while eating 8. Difficulty with wearing dentures 9. Often do things to keep mouth moist 10.Burning, tingling,sensation on the tongue. 11.Fissures & sores at corners of lips. 1. Dryness of lining oral tissues 2. Loss of glistening of the oral mucosa 3. Dryness of the oral mucous membranes 4. Oral mucosa appears thin & pale 5. Tongue blade/mirror/a gloved finger may adhere to the soft tissues 6. Fissuring & lobulation of the dorsum of the tongue & lips 7. Angular cheilitis 8. Candidiasis on tongue & palate 9. Increased incidence of dental caries 10.Thicker, more stringy saliva 11.Swelling of glands 12.Increase in inflammatory gingival diseases 13.Rapid tooth destruction associated with cervical or cemental caries
  56. 56. Treatment of salivary hypofunction & xerostomia : • Systemic Therapy: Bromohexine, anethole, triothiline & pilocarpine Hcl all three should be used under the care of a specialist & following medical examination. • Local Therapy
  57. 57. SALIVARY SUBSTITUTES Carboxy methyl cellulose (CMC) based  Imparts lubrication and viscosity  Sorbitol or xylitol are added to provide surface activity and as a sweetner.  Have surface tension greater than natural saliva. Mucin based Animal mucins derived from procine gastric tissues / bovine salivary glands. Salts are addeded to mimic the electrolyte content of natural saliva
  58. 58. Hypersalivation • It is also known as sialorrhea, ptyalism. • It may lead problems in oral motor coordination, including reduced muscle tone around the mouth & a reduced ability to swallow. • Causes: 1. After extensive surgery for oral or oropharyngeal disorders. 2. As a result of stomatitis, psychological factors, & the use of some drugs, Ex: benzodiazepines,captopril • Treatment i) Drugs – anticholinergics. ii) Surgical – depending on the nature of the anomaly.
  59. 59. SALIVARY MARKERS FOR PERIODONTAL DIAGNOSIS Enzymes Immuno globulins Proteins Phenotypi c markers Host cells Ions Hormone Bacteria Volatile compounds 1.Alpha glucosidase 2.Alkaline Phosphates 3.amino peptidase 4.β galactosidase 5.β- glucosidase 6.collagenase 7.elastase 8.esterase 9.gelatinase 10.kallikrein 11.lysozyme 12. myeloperoxidase 13. trypsin. IgA IgG IgM sIgA 1.Cystatin 2.Epidermal growth factor 3.fibronectin 4. lactoferrin 5.platelet Activating Factor 6.vascular endothelial growth factor Epithelial keratins Leucocyte (PMNs) calcium cortisol A.actinomycetum comitans B.forsythus mycoplasma P.gingivalis P.intermedia P.micros p.nigrescens C.rectus T.denticola Hydrogen sulfide Methyl mercaptan Picolines Pyridines
  60. 60. DIGNOSTIC APPLICATIONS How serum constituents(i.e., drugs and hormones) reach saliva – Within 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. The Monitoring Of Hormone Levels 7. Diagnosis Of Oral Disease With Relevance For Systemic Diseases
  61. 61. COMPARE SALIVA AND SERUM ADVANTAGES DISADVANTAGES collected non-invasively, and by individuals with limited training samples are not sterile and are subject to bacterial degradation over time. No special equipment is needed Absorbing specimens on cotton may contribute interfering substances to the extract children and older adults as fewer compliance problems Interpretation of saliva assays is still difficult Cost-effective approach for the screening of large populations contamination from bleeding gums more accurate reflection of the active hormone, especially for steroid hormones A few kits offer saliva controls with the reagents stable at room temperature for extended periods Hazards associated with blood collection do not apply to saliva multiple samples
  62. 62. FDA APPROVED SALIVARY KITS HIV, Drugs Of Abuse - Orasure Collection System ( Epitope) Steroid Hormones - Diagnostic Systems Laboratories And Salimetrics Secretory Iga And Melatonin - ALPCO
  63. 63. HEREDITARY DISEASES Cystic fibrosis • Elevated levels of calcium and proteins in submandibular saliva • Higher occurrence of calculus (Wotman et al., 1973) • The submandibular saliva contained more lipid • Elevations in electrolytes (sodium, chloride, calcium, and phosphorus), urea and uric acid, and total protein in the submandibuar saliva • Minor salivary glands are also affected • Parotid saliva does not demonstrate qualitative changes • Unusual form of epidermal growth factor (EGF) • Abnormally elevated levels of prostglandins E2 (PGE2) were detected in the saliva
  64. 64. Coeliac disease • Serum IgA antigliadin antibodies (AGA) are increased • Salivary IgA-AGA is a sensitive and specific method for the screening of coeliac disease, and for monitoring compliance with the required gluten-free diet (al-Bayaty et al., 1989; Hakeem et al., 1992). 21-Hydroxylase deficiency • Early morning salivary levels of 17-hydroxyprogesterone (17-OHP) is an excellent screening test for the diagnosis, since the salivary levels accurately reflected serum levels of 17-OHP.
  65. 65. AUTOIMMUNE DISEASES—SJOGREN'S SYNDROME • The accepted investigation of salivary involvement is a biopsy of the minor salivary glands of the lip. • Presence of a lymphocytic infiltrate (predominantly CD4+ T-cells) in the salivary gland parenchyma • A low resting flow rate and abnormally low stimulated flow rate of whole saliva • Elevated levels of rheumatoid factor, antinuclear antibody, anti-SS-A, and anti-SSB • In sialochemistry –increased concentrations of sodium and chloride • Elevated levels of IgA, IgG, lactoferrin, and albumin, and a decreased concentration of phosphate • Increased salivary concentrations of inflammatory mediators—i.e., eicosanoids, PGE2, thromboxane B2, and interleukin-6 • Autoantibody, especially of the IgA class, is detected in the saliva of SS patients prior to detection in the serum
  66. 66. MALIGNANCY • Tumor markers that can be identified in saliva may be potentially useful for screening for malignant diseases – P53 – Defensins – c-erbB-2 (erb) – cancer antigen 15-3 (CA15-3) – CA 125
  67. 67. INFECTIOUS DISEASES • Helicobacter pylori infection • Children infected with Shigella • Pigeon breeder's disease • Pneumococcal pneumonia • Lyme disease • Taenia solium
  68. 68. 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 ).
  69. 69. • 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)
  70. 70. •Salivary proteases, alone or acting synergistically with hyaluronidase, are capable of penetrating oral epithelium in areas of irritation & lysing the collagen fibers & ground substance in the underlying connective tissue.This could render a region more susceptible to bacterial invasion.( JADA vol 30, 1961 ). •Watanable et al. found positive relationships between salivary protease activity & calculus index, as well as between protease activity & periodontal pocket depth. •According to Nakamura & Slots, increased activity for alkaline phosphatase, esterase, beta-glucosidase & other aminopeptidases was detected in saliva from patients with chronic periodontitis, compared to healthy controls, but patients with aggressive periodontitis exhibited greater amounts of salivary butyrate esterase & cysteine aminopeptidase.
  71. 71. • Uittto et al. investigated increased collagenase activity in periodontal patients compared to controls. Collagenase is one of the important matrix metalloproteinases responsible for the degradation of connective tissue. Because of its key role in this process, collagenase in saliva may reflect the status of periodontal health. . • Zambon et al. found reduced amounts of leucine, valine, cysteine aminopeptidases, caprylate esterase lipase, trypsin, beta-galactosidase, beta-glucoronidase, & beta-glucosidase in whole saliva from chronic periodontitis patients after periodontal therapy.The propotions of subgingival black-pigmented bacteriods & motile organisms also decreased in those patients.
  72. 72. •Makela et al. found the concentration of matrix metalloproteinase-9 (MMP-9 or 92 kDa gelatenase ) was significantly higher in whole saliva of periodontitis patients compared with healthy subjects, & that periodontal treatment resulted in reduced amounts of those enzymes. •Hayakawa et al. reported that total TIMP-1 ( tissue inhibitor of metalloproteinase-1 ) concentration in whole saliva of periodontally patients was clearly lower than that of clinically healthy subjects. •Studies have also shown that, the levels of aspartate aminotransferase (AST) in saliva from patients presenting CPITN code 4 were higher than from patients coded lower & could be detected by the evaluated diagnostic system. Periodontal destruction such as periodontal pockets, gingival bleeding & suppuration seems to be related to higher AST levels.
  73. 73. •In periodontal patients we can see the lower levels of lysozyme concentration & higher levels of Myeloperoxidase ( MPO ). •Patients with aggressive periodontitis are associated with significantly elevated antibodies to A.actinomycetemcomitans, P.gingivalis, T.denticola, & F.nucleatum compared with healthy controls. •The leukotoxin produced by A.actinomycetemcomitans & proteases produced by P. gingivalis are examples of factors that are believed to destroy neutrophils or affect their function in aggressive periodontal patients.
  74. 74. 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.
  75. 75. RESEARCH APPLICATIONS Research currently is being conducted to • saliva as a diagnostic aid for cancer and preterm labor. • regenerative properties and functions of growth factors found in saliva, such as EGF, TGF
  76. 76. CONCLUSIONS •Saliva is an alternative to serum as a biological fluid that can be analysed for diagnostic purposes. •A number of markers show promise as sensitive measures of the disease & the effectiveness of therapy. • 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.
  77. 77. REFERENCES 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.
  78. 78. Antibacterial Factors • Mucins:  High molecular weight glycoproteins  Lubricate the oral surfaces  Exhibit some specificity for complexing oral bacteria,enhancing elimination .  Help in prevention of dehydration of the oral epithelia, lubrication for solid food & trapping of microorganisms.
  79. 79. • Lactoferrin :  Derived from serous glands and gingival fluid  Mediates its antibacterial effects through binding of iron necessary for bacterial metabolism.  Inhibition of bacterial adhesion to tooth surfaces.  Activates phagocytic cells.  It is effective against actinobacillus species. • Lysozyme : Derived from the ductal epithelium of the salivary glands.It provides 1. Muramidase activity ( lysis of peptidoglycan layer) 2.Cationic- dependent activation of bacterial autolysins 4.Inhibition of bacterial adhesion to the tooth surfaces. 5.Inhibition of bacterial glucose uptake & acid production 6.De-chaining of streptococci
  80. 80. • Histidine rich proteins ( histatins): Antifungal particularly against the C. albicans. • Proline rich proteins exhibit selective binding of certain oral species, which may be beneficial to blocking more pathogenic species. • Salivary peroxidase : 1. It acts on substrates in the saliva to form hypothiocyanate ions, which are toxic to certain bacteria. 2.Inactivation of bacterial glucolytic enzymes 3.Inhibition of bacterial uptake & acid production 4.Inhibition of bacterial transport of aminoacids 5.Damage of bacterial cell wall 6.Inhibition of bacterial adhesion to saliva coated hydroxy apatite.
  81. 81. • Lactoperoxidase-thiocyanate system - Bactericidal to lactobacillus & streptococcus by preventing the accumulation of lysine & glutamic acid, both of which are essential for bacterial growth. • Myeloperoxidase : Realeased by leukocytes & is bactericidal for Actinobacillus & it inhibits attachment of Actinomyces strains to hydroxyapatite. • Cystatins ( Cysteine Protinase inhibitors):  Constitutively secreted in saliva  CystatinC levels are increased following severe inflammation in periodontitis
  82. 82. • VonEbner glands protein (VEGh):  Secreted by the Von ebner glands.  Also known as “ tear specific pre albumin (TSPA)”.  Belongs to Lipocalin super family  Acts as an oxidative stress induced scavenger of peroxidation products. • Immunoglobulins :  Saliva contains antibodies that are reactive with indigenous oral bacterial species  The predominant immunoglobulin is IgA, although IgM & IgG are present.  IgA antibodies present in parotid saliva can inhibit the attachment of oral streptococcus species to epithelial cells.
  83. 83. Coagulation Factors • Saliva also contains coagulation factors ( viii, ix, Plasma Thromboplastin Antecedent, & the Hageman factor) that hasten blood coagulation & protect wounds from bacterial invasion. • The presence of an active fibrinolytic enzyme has been suggested.

Notas del editor

  • Individual salivary glands arise as a proliferation of oral epithelial cells, forming a focal thickening that grows into the underlying ectomesenchyme.
    2.These long epithelial cords undergo repeated dichotomous branching, called, “ Branching morphogenesis”, that produces successive generations of buds & a hierarchial ramification of the gland & the mesenchymal cells condense around the bud.
  • The development of a lumen within the branched generally occurs first in the distal end of the main cord & finally in the central portion of the main cord.

    4.The lumen form within the ducts before they develop within the terminal buds.

    5.Some studies have suggested that lumen formation may involve the apoptosis of centrally located cells in the cords.
  • 6.Following development of the lumen in the terminal buds, the epithelium consists of two layers of cells.

    a) The cells of the inner layer eventually differentiate into the secretory cells of the mature gland, mucous / serous.
    b) Some cells of the outer layer form the contractile myoepithelial cells that are present around the secretory end pieces & intercalated ducts.
    7.As the epithelial parenchymal components increase in size & number, the associated mesenchyme ( connective tissue ) is diminished, although a thin layer of connective tissue remains, surrounding each secretory end piece & duct of the adult gland.