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  • As saliva passes through the salivary ducts, cations (sodium and chloride) are reabsorbed into the adjacent blood vessels. <br />
  • In exchange, the body releases bicarbonates and potassium. <br />
  • Stimulated salivary flow causes rapid passage through the salivary duct and thus impedes the exchange of sodium and chloride for potassium and bicarbonate. <br /> Unstimulated salivary flow is slower and thus has a high content of potassium and bicarbonate. <br /> The quality of unstimulated saliva will change when flow increases because of a stimulus (chewing gum, thinking about lemons, looking at a food you crave). <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • 1.5.6-7.8 ph <br /> 2. lavage, lubrication, pellicle (calcium binding proline-rich salivary proteins)= protection <br /> 3. toothbrush, sialin, calculus <br /> 4. Candida albicans <br /> 4. Digestion---bolus <br /> 5. Speech, repair of tissue <br />
  • Automatic, and predictable responses to stimuli. <br /> Dependent on reflex activity . <br /> Vary depending on the stimuli. <br />
  • Sour: evokes the greatest salivary response. <br /> Chew on the right side of the mouth- inc. in salivary response from the right parotid <br /> Story of Pavlov and the Dog. <br />
  • No significant evidence. When hungry, we become more aware of the presence of saliva in our mouth. <br /> Trauma during tooth extraction or spicy food. <br /> Experienced when one gets heartburn or the feeling of nausea. Believed to be due to the high levels of acidity in the esophagus. <br />

salivary gland and saliva darpan salivary gland and saliva darpan Presentation Transcript

  • Salivary gland And Role of saliva in maintaining oral health Darpan Nenava PG 1st year 1
  • CONTENTS   INTRODUCTION ANATOMY OF SALIVARY GLANDS          PAROTID GLAND SUBMANDIBULAR GLAND SUB LINGUAL GLAND EMBRYOLOGY HISTOLOGY PHYSIOLOGY SALIVA CONCLUSION REFERENCES 2
  • Introduction  Salivary glands are group of compound exocrine glands secreting saliva.  Parenchymal elements consists of terminal secretory units leading into ducts.  Connective tissue forms a capsule around a gland, and extend into it dividing groups of secretory units & ducts into lobes & lobules.  Tubulo acinar units are merocrine 3
  • Introduction  Salivary Gland is any cell or organ discharging a secretion into the oral cavity.  Major and minor Salivary Glands  Major (Paired)  Parotid  Submandibular  Sublingual  Minor  Those in the Tongue, Palatine Tonsil, Palate, Lips and Cheeks 4
  • Anatomy of salivary glands 5
  • Parotid Gland  Largest  Average Wt - 25gm  Irregular lobulated mass lying mainly below the external acoustic meatus between mandible and sternomastoid.  On the surface of the masseter, small detached part lies b/w zygomatic arch and parotid ductaccessory parotid gland or ‘socia parotidis’ 6
  • Parotid Capsule  Derived from investing layer of deep cervical fascia.  Superficial lamina-thick, closely adherent-sends fibrous septa into the gland.  Deep lamina-thin- attached to styloid process,mandible and tympanic plate.  Stylomandibular ligament. 7
  • External Features  Resembles an inverted 3 sided pyramid  Four surfaces Superior(Base of the Pyramid)  Superficial  Anteromedial  Posteromedial   Separated by three borders Anterior  Posterior  Medial  8
  •  Superior Surface Relations Concave  Related to  Cartilaginous part of ext acoustic meatus  Post. Aspect of temperomandibular joint  Auriculotemporal Nerve  Sup. Temporal vessels   Apex  Overlaps posterior belly of digastric and adjoining part of carotid triangle 9
  •  Superficial Surface  Covered by Skin  Superficial fascia containing facial branches of great auricular N  Superficial parotid lymph nodes and post fibers of platysma   Anteromedial Surface  Grooved by posterior border of ramus of mandible  Related to Masseter  Lateral Surface of temperomandibular joint  Medial pterygoid muscles  Emerging branches of Facial N  10
  •  Posteromedial Surface  Related  to mastoid process with sternomastoid and posterior belly of digastric.  Styloid process with structures attached to it.  External Carotid A. which enters the gland through the surface  Internal Carotid A. which lies deep to styloid process 11
  • Borders  Anterior border  Separates superficial surface from anteromedial surface.  Structures border which emerge at this  Parotid Duct  Terminal Branches of facial nerve  Transverse facial vessels 12
  •  Posterior Border  Separates superficial surface from posteromedial surface  Overlaps sternomastoid  Medial Border  Separates anteromedial surface from posteromedial surface  Related to lateral wall of pharynx 13
  • Structures within Parotid Gland tempora l  External carotid A  Retromandibular Vein  Facial Nerve Zygomaticotemporal zygomatic Facial Nerve buccal mandibula r cervical Superficial temporal V Maxillary V Post auricular V External jugular Cervicofacial Superficial temporal A Maxillary A P.Auricular A Common Facial V 14
  •  Facial Nerve trunk lies approximately 1 cm inferior and 1 cm medial to tragal cartilage pointer of external acoustic meatus. 15
  • Parotid Duct  Ductus parotideus; Stensen’s duct  5 cm in length  Appears in the anterior border of the gland  Runs anteriorly and downwards on the masseter b/w the upper and lower buccal branches of facial N. 16
  •  At the anterior border of masseter it pierces     Buccal pad of fat Buccopharyngeal fascia Buccinator Muscle It opens into the vestibule of mouth opposite to the 2nd upper molar 17
  • Surface anatomy of Parotid Duct  Corresponds to middle third of a line drawn from lower border of tragus to a point midway b/w nasal ala and upperlabial margin 18
  • Blood supply  Arterial   Branches of Ext. Carotid A Venous  Into Ext. Jugular Vein Lymphatic Drainage Upper Deep cervical nodes via Parotid nodes 19
  • Nerve Supply  Parasymapthetic N  Secretomotor via auriculotemporal N  Symapathetic N  Vasomotor  Delivered from plexus around the external carotid artery  Sensory N  Reach through the Great auricular and auriculotemporal N 20
  • Clinical Consideration 1. 2. 3. A viral inflammation of the parotid gland (mumps) causes it to swell, resulting to pain on movement of the jaw. Abcesses or cysts of the gland may result in pressure to the facial nerve Stones or calculi in the duct can block it, causing painful swelling of the gland. 21
  • Submandibular Salivary Glands  It is a mixed serous and mucous secreting gland.  Irregular in shape  Large superficial and small deeper part continous with each other around the post. Border of mylohyoid  Superficial Part    Situated in the digastric triangle Wedged b/w body of mandible and mylohyoid 3 surfaces  Inferior,Medial,Lateral 22
  • 23
  •  Capsule  Derived from deep cervical fascia  Superficial  Deep Layer is attached to base of mandible layer attached to mylohyoid line of mandible 24
  •  Relations  Inferior- covered by       Skin Supeficial fascia containing platysma and cervical branches of facial N Deep Fascia Facial Vein Submandibular Nodes Lateral surface    Related to submandibluar fossa on the mandible Madibular attachment of Medial pterygoid Facial Artery 25
  •  Medial surface  Anterior part is related to myelohyoid muscle,nerve and vessles  Middle partHyoglossus,styloglossus,lingual nerve, submandibular ganglion,hypoglossal nerve and deep lingual vein.  Posterior Part-Styloglossus,stylohyoid ligament,9th nerve and wall of pharynx 26
  •  Deep part  Small in size  Lies deep to mylohyoid and superficial to hyoglossus and styloglossus  Posteriorly continuous with superficial part around the posterior border of mylohyoid 27
  •  Submandibluar duct Whartons duct  5 cm long  Emerges at the anterior end of deep part of the gland  Runs forwards on hyoglossus b/w lingual and hypoglossal N  At the ant. Border of hyoglossus it is crossed by lingual nerve  Opens in the floor of mouth at the side of frenulum of tongue  28
  • 29
  • Blood Supply  Arteries  Branches of facial and lingual arteries  Veins  Drains to the corresponding veins  Lymphatics  Deep Cervical Nodes via submandibular nodes 30
  •  Nerve Supply  Branches from submandibular ganglion, through which it receives  Parasymapthetic fibers from chorda tympani  Sensory fibers from lingual branch of mandibular nerve  Sympathetic fibers from plexus on facial A 31
  • Sublingual Salivary Glands  smallest of the three glands  weighs nearly 3-4 gm  Lies beneath the oral mucosa in contact with the sublingual fossa on lingual aspect of mandible. 32
  •  Relations  Above  Mucosa of oral floor, raised as sublingual fold  Below   Myelohyoid Infront Anterior end of its fellow  Behind  Deep part of Submandibular gland 33
  •  Lateral  Mandible above the anterior part of mylohyoid line  Medial  Genioglossus and separated from it by lingual nerve and submandibular duct 34
  •  Duct Ducts of Rivinus  8-20 ducts  Most of them open directly into the floor of mouth  Few of them join the submandibular duct  35
  •  Blood supply Arterial from sublingual and submental arteries  Venous drainage corresponds to the arteries   Nerve Supply  Similar to that of submandibular glands( via lingual nerve , chorda tympani and sympathetic fibers) 36
  •  Minor salivary glands are found throughout the mouth: – Lips – Buccal mucosa (cheeks) – Alveolar mucosa (palate) – Tongue dorsum and ventrum – Floor of the mouth  Together, they play a large role in salivary production. 37
  • Minor salivary glands 38
  • Embryology 39
  • PRIMORDIA TIME OF DEVELOPMEN T EMBRYONIC ORIGIN REGION Parotid gland primordia (anlage) 5th to 6th week Ectoderm Labiogingival sulcus Submandibular gland primordia 6th week Endoderm Hyoid arch Endoderm Linguogingival sulcus Sublingual gland 7th to 8th week primordia Intraoral minor salivary glands 3rd month 40
  • Development of Salivary Glands 41
  • Histology 42
  •  Compound Tubuloalveolar glands  Structure   Closely packed acini or alveoli with ducts scattered in between Supported by connective tissue which divides the gland into lobules 43
  •  Cells lining the alveoli Serous or mucous Serous      Stain darkly (zymogen granules) Wedge shaped with round nucleus, lying towards the base Mucous      Lightly stained Appears empty Polyhedral Contain mucinogen granules Nucleus flattened ,close to the basement membrane 44
  •  Parotid   Parotid Sublingual   Serous type Mucous Submandibular  Mixed type –some mucous alveoli capped by serous cresents – ‘Demilunes’ Sublingual Submandibular 45
  • DUCTS 46
  • DUCTS Intralobular Intercalated Striated Intralobular Excretory 47
  • DUCTS 48
  •  Myoepithelial cells  Present in relation to alveoli and intercalated ducts  Those on the alveoli are branched-’Basket Cells’  Those on the ducts are fusiform  Contractile cells helps to squeeze out secretions from alveoli 49
  • Physiology 50
  •  Main function of Salivary Gland-secretion of saliva  Daily secretion -800 to 1500 ml  pH : 6-7 51
  • Control of Salivary Secretion Sup Salivatory Nu Facial N Otic Ganglion Inf Salivatroy Nu Parotid Gland Chorda tympani N Submandibular G  Under neural control  Mainly by parasympathetic signals from Sup & Inf salivatory nuclei 52
  •  Parasympathetic stimulationprofuse secretion of watery saliva  Sympathetic stimulationscanty viscid secretion  Sympathetic supply comes from cervical sympathetic chain along the blood vessels 53
  •  Salivatory nuclei are excited by  Taste and tactile stimuli from tongue and other areas of mouth and pharynx  Stimuli from esophagus and stomach (due to stimulation of vagal afferent fibers)  (unconditioned reflex)  Stimuli arising from higher centers of brain due to sight, smell or thought of food  (conditioned reflex). 54 Pavlov with his dog
  • SALIVA 55
  •  Complex fluid found lubricating the mucosa and teeth of the oral cavity.  Salivary glands, their cells and ducts are greatly responsible for the modification and kind of saliva being secreted  It is of three types:    Serous Saliva Mucous Saliva Mixed Saliva 56
  •  General characteristics:  Consistency - slightly cloudy due to presence of mucins and cells  Reaction - usually slightly acidic (pH 6.02-7.05).On standing or boiling, it loses CO2 and becomes alkaline.  Specific gravity - 1.002-1.012  Freezing point - 0.07-0.34° Celsius 57
  •  58 Percentage contribution of different salivary glands during unstimulated saliva:
  • Unstimulated flow  Resting salivary flow―no external stimulus o Typically 0.2 mL – 0.3 mL per minute o Less than 0.1 mL per minute means the person has hyposalivation Hyposalivation – not producing enough saliva 59
  • Stimulated Flow  Response to a stimulus, usually taste, chewing, or medication eg, at mealtime o Typically 1.5 mL – 2 mL per minute o Less than 0.7 mL per minute is considered hyposalivation 60
  • The average person produces approximately 0.5 L – 1.5 L per day • Salivary flow peaks in the afternoon • Salivary flow decreases at night. • There is a difference in the quality between stimulated and unstimulated saliva 61
  • Ions and salivary flow As saliva passes through the salivary ducts, cations (sodium and chloride) are reabsorbed into the adjacent blood vessels. 62
  • As saliva passes through the salivary ducts, cations (sodium and chloride) are reabsorbed into the adjacent blood vessels. In exchange, bicarbonates and potassium are transferred from the blood 63
  • Stimulated Salivary Flow • Saliva passes through the salivary duct very rapidly o It impedes the exchange of sodium and chloride for potassium and bicarbonate Unstimulated Salivary Flow • Has a high content of potassium and bicarbonate o The quality of unstimulated saliva will change when flow increases because of a stimulus (chewing gum, thinking about lemons, looking at a food you crave) 64
  • Saliva Compositon Water (99.5%) Solid (0.5%) Organic Ptyalin Mucin Lysozyme IgA Lactoferrin Inorganic Na+ K+ Ca+ ClHCO3 Mg 65
  •  Ionic Composition  Saliva in the acini-isotonic with plasma  Under resting condition ionic composition of saliva reaching the mouth     During    Na+ and Cl- 15 mEq/l (1/7 to 1/10 conc of Plasma) K+ 30 mEq/l (7 times that of Plasma) HCO3- 50-70 mEq/l (2-3 times that of plasma) maximal salivation Na+ and Cl- (1/2 to 2/3 conc of Plasma) K+ (4 times that of Plasma) HCO3- 50-70 mEq/l (2-3 times that of plasma) 66
  • Functions of Saliva   Main function: maintaining the well-being of the mouth Other important functions:  Protection  Buffering Action  Digestion  Facilitation of Taste  Defensive Action against Microbes  Ionic Exchange between Tooth Surface 67
  • Functions of Saliva Effect Active Constituent Protection Lubrication, lavage, pellicle formation Glycoprotein Water Buffering Action Regulates pH Phosphate and Bicarbonate Digestion Digests starch Digests lipids Bolus formation Amylase Lingual Lipase Facilitation of Taste Taste bud growth and maturation, dissolves substances to carry to taste buds Gustin Defensive Action Against Microbes Antibodies Hostile Environment Lysozyme Lactoferrin IgA Ionic Exchange Between Tooth Surface Posteruptive Maturation of Enamel Repair Calcium Phosphate 68
  • Saliva and Dental Caries       Effect of desalivation and hyposalivation on dental caries Salivary clearance from oral cavity Flouride concentration of saliva Salivary antibacterial substance Protein inhibiting hydroxyapatite Acquired salivary pellicle 69
  • Effect of desalivation and hyposalivation on dental caries   Total or partial aplasia is rare and accompanied by high caries prevalence Causes Tumor growth  Radiation therapy     This condition is called as XEROSTOMIA Reduced salivary secretion is called as HYPOSALIVATION Causes        Drugs such as atropine and other anticholinergics Fever or prolonged diarrhea Diabetes Anemia Hypovitaminosis A or B Uremia Dehydrating disease of old age 70
  •  Patients with hyposalivation experience Difficulty in mastication  Swallowing  Wearing dentures  Speaking   Sjogren’s syndrome is an autoimmune Acinar cells are destroyed  Dry eyes as lacrimal gland cells are also destroyed  And symptoms of rheumatoid arthritis  71
  • Salivary clearance from oral cavity  Role of bacteria and food debris removal from oral cavity  Bacteria   Bacteria is passed into stomach by salivary flow Half life of any material in cavity is only few minutes  Despite continuous flow dental plaque can accumulate at rapid rate of 10-20mg/day  Rate of plaque accumulation is even more rapid in patients with hyposalivation and xerostomia 72
  •  Food Debris When retained in mouth act as substrate for metabolic activities of microbes  Thus if clearance is retarded it will tend to promote the development of caries  Caramel and other toffees show prolonged retention  Some studies show cariogenecity is not related to sugar concentration   Sugar in non retentive forms as in soft drinks 73
  • Flouride concentration of saliva    The level of flouride ions in ductal saliva is as low as 0.010.03ppm. Flouride level in saliva are independent of salivary flow rate and determined by the amount ingested Fluorapatite     Insoluble in saliva Therefore beneficial to have high proportion of fluorapatite in surface enamel as possible Higher stable concentration of fluoride can accure slowly from saliva But can be reached more rapidly by topical flourde applications 74
  • Flouride concentration of saliva  The importance of fluoride maintenance and augmentation of fluoride in enamel surface  As the fluoride concentration is reduced protection against caries is also decreased 75
  • Salivary antibacterial substance  A number of anti bacterial factors present in saliva      Lysozymes Lactoperoxidase Lactoferrin Immunoglobulin A It helps to prevent the establishment of more pathogenic transient invaders 76
  • Lysozymes  Have property of cleaving cell walls of microbes causing there lysis  Antibacterial action of lysozyme does not completely depend on cell lysis  (Streptococcus mutans lose there viability in the presence of lysozyme and some detergent or NaCl without lysis of cell wall 77
  • Lactoperoxidase     This factor exists in milk, saliva and tears and can inhibit the growth and acid formation of some bacteria. It oxidises thiocyanate (SCN-) in presence of hydrogen peroxide Formed by microbes in hypothiocyanate(OSCN-) To oxidize thiol group which leads to activation of many bacterial enzymes 78
  • Lactoferrin  Bacteriocidal effects due to its strong iron binding capacity Removing iron from solution and making it unavailable as an essential bacterial nutrient  Lactoferrin has been shown to be antagonist to S.mutans  79
  • Immunoglobulins  There are two principal immunological mechanism involved in protection against infectious diseases  Antibodies production (humoral immunity)   Involving cells (cell-mediated immunity)   Antibodies produced by plasma cells circulate in body (systemic immunity) If produced by plasma cells with secretory tissues such as salivary gland (local immunity) Antibodies are      IgG IgA IgD IgE IgM 80
  • Immunoglobulins     In systemic circulation IgG dominates In saliva IgA dominates in S-IgA form Secretory Immunoglobulin A Concentration of IgA in stimulated parotid and submandibular saliva is 4mg/100ml 30mg/100ml in secretion from minor salivary glands 81
  • Protein inhibiting hydroxyapatite  Several salivary protein bind calcium and /or inhibit formation of hydrooxyapatite these proteins are  Statherin  Proline-Rich Proteins 82
  • Protein inhibiting hydroxyapatite  Statherin      A polypeptide Concentration in saliva 2-6 µM Also prevents precipitation of calcium phosphate from supersaturated solution by adsorbing onto early crystal nuclei Causing demineralization of early carious lesion Inhibition is due to the ability of the statherin to block crystal growth of calcium phosphate 83
  • Protein inhibiting hydroxyapatite  Proline-Rich Proteins      A polypeptide Concentration in saliva 2-6 µM Also prevents precipitation of calcium phosphate from supersaturated solution by adsorbing onto early crystal nuclei Causing demineralization of early carious lesion Inhibition is due to the ability of the statherin to block crystal growth of calcium phosphate 84
  • Acquired salivary pellicle 85
  • Acquired salivary pellicle  Clinical relevance     Pellicle thickness   To prevent the contact of saliva prior to composite resin placement Upon the etched enamel Salivary protein tend to fill up defects in newly etched enamel 100nm after 2 hrs to about 400nm in 24-48 hrs Pellicle is three layered    Subsurface :- has dendritic appearance penetrate in pores and demineralized enamel Centre :- uniformly forms a surface around tooth Suprastructure :- variable thickness 86
  • Acquired salivary pellicle     This is predominantly bacteria free initially Becomes highly insoluble with time due to protein denaturation Coating becomes rapidly populated by mixed bacterial aggregrates Grow in number and coalesce to form bacterial dental plaque 87
  • Properties of salivary pellicle       Act as a lubricant prevent premature loss of enamel during mastication Reduces rate of demineralization of tooth surface by acidic food and drinks Act as a semi permeable membrane and reduces ion mobility but the movement of water is unaffected. Reduces mobility of calcium and phosphate from enamel to fluid enviorment Forms a surface for bacterial colonization leads to formation of microbial dental plaque Prevents continuous enlargement of tooth surface by crystal growth of hydroxyapatite crystal 88
  • Amylases, Cystatins, Histatins, Mucins, Peroxidases Cystatins, Mucins Histatins AntiBacterial AntiViral AntiFungal Buffering Salivary Functions Carbonic anhydrases, Histatins Digestion Mineralization LubricatTissue ion &ViscoCoating elasticity Amylases, Cystatins, Mucins, Proline-rich proteins, Statherins Amylases, Mucins, Lipase Cystatins, Histatins, Prolinerich proteins, Statherins Mucins, Statherins 89
  • SALIVATION REFLEX ACTIVITY 90
  • Reflex Activity    Resting flow: keeps the mouth and oropharynx moist Food and the prospect of eating: are most saliva-inducing stimuli Whole-mouth saliva contribution when stimulated:    Parotid gland: 50% Submandibular gland: 30% Sublingual and minor salivary glands: 20% 91
  • Reflexes  Gustatory-salivary reflex  Sour>salty>sweet>bitter  Masticatory-salivary reflex  Saliva  flow is directly proportional to masticatory forces Olfactory-salivary reflex  No reflex response from the parotid gland  Increase in salivary secretion from the submandibular and sublingual glands 92
  • Reflexes  Visual and psychic salivary reflex  Stimuli:  thought and sight of food Esophageal-salivary reflex  Waterbrush phenomenon: sudden filling of the mouth with fluids 93
  • AGE CHANGES 94
  • Age Changes  the aging salivary glands are known to undergo structural changes The lobule structure becomes less ordered  The acini vary more in size and eventually atrophy  Interlobular ducts become more prominent and the percentage of fibroadipose tissue increases  95
  • Age Changes  Changes in the salivary glands (submandibular,parotid (less) and minor salivary glands)  Shrinkage of cells  Dilation of ducts  Oncocytic transformation  Increased adiposity  Fibrosis  Focal microcalcifications with obstruction  Chronic inflammation 96
  • CLINICAL CONSIDERATIONS 97
  • Mucoceles    CAUSE: trauma to excretory ducts of the minor glands which allows the spillage of mucus into the surrounding connective tissue PHYSIOLOGIC MANIFESTATION: formation of painless, smooth surfaced, bluish lesions TREATMENT: self-limiting (acute) or surgery (chronic) 98
  • Mucocele 99
  • Ranulas    Type of mucocele CAUSE: blocked sublingual gland ducts PHYSIOLOGIC MANIFESTATION: Unilateral, softtissue lesions, often with a bluish appearance.   Vary in size and may cross the midline of the mouth and cause deviation of the tongue TREATMENT: self-limiting (acute) surgery (chronic) 100
  • Ranula 101
  • Sialolithiasis  CAUSE: inactivity of the glands Metabolic conditions that promote salt precipitation in the glands  Predisposing factors: dehydration and poor oral hygiene    PHYSIOLOGIC MANIFESTATION: formation of caliculi TREATMENT: massaged out by a specialist, surgery, antibiotics 102
  • Sialolithiasis 103
  • Necrotizing Sialometaplasia  UNKNOWN CAUSE    Possible etiologic agent: smoking, trauma, vascular disease PHYSIOLOGIC MANIFESTATION: uncommon benign lesion and inflammatory condition that affects salivary glands, usually the minor salivary glands TREATMENT: resolves spontaneously, self-limiting 104
  • Necrotizing Sialometaplasia 105
  • Mumps      Aka. epidemic parotitis (viral) Occurs usually during childhood CAUSE: paramyxovirus that infects the parotid glands PHYSIOLOGIC MANIFESTATION: inflammation of the parotid glands located on either side of the face TREATMENT: warm compress, warm, salt water rinses, antibiotics, surgery, anti-inflammatory medications 106
  • Mumps 107
  • Salivary Gland Neoplasm     Aka. Salivary gland cancer CAUSE: rapid cell growth of the salivary gland PHYSIOLOGIC MANIFESTATION: present as painless, slow-growing masses TREATMENT: radiation therapy, chemotherapy 108
  • Salivary Gland Neoplasms 109
  • Irradiation Reaction (Xerostomia)     subjective complaint of dry mouth due to a lack of saliva CAUSE: tumoricidal doses of ionizing radiation, excessive clearance or breathing through the mouth, hyposalivation (decreased saliva production) PHYSIOLOGIC MANIFESTATION: dry oral mucosa TREATMENT: frequent sips of water and frequent mouth care 110
  • Xerostomia 111
  • thank you 112