Recommended
More Related Content
What's hot
What's hot (20)
Similar to Saliva & Salivary glands A Prosthodontics Perspective
Similar to Saliva & Salivary glands A Prosthodontics Perspective (20)
Recently uploaded
Recently uploaded (20)
Saliva & Salivary glands A Prosthodontics Perspective
- 1. Saliva and salivary glands A prosthodontics perspective… GUIDED BY : DR. SHAILENDRA KUMAR SAHU DR. ANURAG DANI BY: DR. AAYUSH SHAH
- 2. CONTENTS: INTRODUCTION EMBYROLOGY AND DEVELOPMENT SALIVAY GLANDS : STRUCTURE CLASSIFICATION SALAIVA: FORMATION COMPOSITION FUNCTION REGULATION OF SALIVARY GLANDS PROSTHODONTICS PERSPECTIVE REFRENCES
- 3. Introduction: Salivary glands are compound tubuloacinar exocrine glands present in the oral cavity that secretes saliva. Saliva is watery liquid secreted into the mouth by glands, providing lubrication for chewing and swallowing, and aiding digestion.
- 4. Defintions: • “Saliva is a clean, tasteless, odorless slightly acidic viscous fluid, consisting of secretions from the parotid ,sublingual , submandibular glands and the mucous glands of oral cavity” A.K.Jain’s Human physiology,5th edition • “Saliva is a complex fluid produced by salivary glands,the most important function of which is to maintain the well being of oral cavity.”Tencates book of oral histology
- 5. Embryology and development : The development of salivary glands is the result of highly complex interaction between the oral epithelium and the underlying mesenchymal cells All the salivary glands share a common path of growth Epithelial cells carry the information of the type of secretions Mesenchymal cells carry information of the type of branching that eventually will be the morphological structure of the glands Gland Location IU LIFE Parotid gland Corner of the stomodeum 6th week Submandibular salivary gland Floor of the mouth 7TH week Sublingual salivary gland Lateral to mandibular primordium 8th week Minor salivary glands Buccal epithelium After 12th week
- 6. Stages of salivary gland development : PREBUD STAGE INITIAL BUD STAGE PSEUDOGLANDULAR STAGE CANALICULAR STAGE TERMINAL BUD STAGE
- 7. Salivary glands structure : Cellular structure of salivary glands include cells like : 1.Serous acini 2.Mucous acini 3.Myoepithelial cells 4.Striated salivary glands 5.Excretory ducts
- 8. Classification of salivary glands According to the anatomy Major glands : 1. Parotid gland 2. Sublingual salivary gland 3. Submandibular salivary gland Minor glands : 1. Labial and buccal glands 2. Glossopalatine glands 3. Palatine glands 4. Lingual glands 5. Von Ebner's salivary glands According to secretions : 1. Serous : 1. Parotid 2. Von ebner 2. Mucous : 1. Palatine 2. Glossopalatine 3. Posterior part of the tongue 3. Mixed : 1. Submental 2. Submandibular
- 9. Parotid glands • Largest salivary gland • Provides 60 – 65% of salivary volume • Shape – pyramidal • Parotid duct – Stensen’s duct • Blood Supply External carotid artery and its branches that arise within the gland. The veins drain into the external jugular vein and internal jugular vein. • Nerve supply Parasympathetic- auriculotemporal nerve Sympathetic -derived from the plexus around the middle meningeal artery Parotid fascia-greater auricular nerve • Lymphatic drainage first to the parotid nodes and from there to the upper deep cervical nodes
- 10. Submandibular salivary glands : Provides 20-30% of total saliva Shape – walnut shaped Duct – Wharton’s duct • Blood supply: It is supplied by the facial artery. • Nerve supply: It is supplied by branches from the submandibular ganglion. • Lymphatic drainage: The veins drain into the common facial or lingual vein. Lymph passes to submandibular lymph nodes.
- 11. Sublingual salivary glands: • This is smallest of the three salivary glands. • It is almond shaped and weighs about 3 to 4g • About 15 ducts emerge from the gland. Most of them open directly into the floor of the mouth on the summit of the sublingual fold. • The gland receives its blood supply from the lingual and submental arteries. The nerve supply is similar to that of the submandibular gland.
- 12. Minor salivary glands : • Located beneath the epithelium of the oral cavity • They are most numerous in the buccal, labial, palatal, and lingual regions. • It has been estimated that there are more than 750 minor salivary glands. • Types: Palatine Glossopalatine Labial Buccal Lingual
- 13. Nerve supply:
- 14. Blood supply:
- 15. Formation of saliva • salivary glands are controlled mainly by parasympathetic nervous signals all the way from the superior and inferior salivatory nuclei in the brain stem. • Salivation can also be stimulated or inhibited by nervous signals arriving in the salivatory nuclei from higher centers of the central nervous system. • Salivation also occurs in response to reflexes originating in the stomach and upper small intestines—particularly when irritating foods are swallowed or when a person is nauseated because of some gastrointestinal abnormality.
- 16. The acinar cells secrete the initial saliva, which is isotonic. The ductal cells modify the initial saliva. There is net absorption of solute because more NaCl is absorbed than KHCO3 is secreted. Because ductal cells are water impermeable, water is not absorbed along with the solute, making the final saliva hypotonic. whole saliva secretion varies between 800- 1500 ml / day or 1.0 to 3.0 ml / minute with a pH in the range of 6-7 for unstimulated whole saliva.
- 17. Composition:
- 18. Functions: • Digestion • Protection [lubrication] • Buffering • Antimicrobial action • Taste • Maintenance of tooth integrity [stetherin,fluoride] • Tissue repair
- 20. Pre- treatment evaluation : Major salivary glands orifices should be examined to ensure they are open. The amount and consistency of saliva affects denture retention and construction. Amount of saliva can be classified as: • Class I: Normal • Class II: Excessive • Class III: Xerostomia
- 21. During impressions: In patients with xerostomia - A very careful gentle approach is essential for patients with dry mouth as the mucosa and lips are easily traumatized. The lips should be coated with petroleum jelly to help with retraction and access to the oral cavity. The operator’s gloved fingers should be wetted to prevent them from sticking to the soft tissues. - A mirror should be used to facilitate insertion of the tray as it is less bulky than the fingers.
- 22. How to control salivary flow: Antisialogauge Mouth rinses Gauze packs Astringent mouthwash gauze sponges dampened in warm water should be used to place pressure over the posterior palate, causing the palatal glands to empty. 1. propantheline bromide . 2.Methanthelene bromide Contraindicated in Glaucoma. Prostatic hypertrophy. Cardiac conditions .
- 23. If saliva is retained on impression and cast is poured, this results in a cast with rough surfaces . Thin and serous saliva • removed by holding the impression under a gentle stream of cool tap water. • using a soft camel hair brush Thick and ropy saliva • a thin layer of dental stone be sprinkled on the surface of the impression. • The stone adheres to the saliva and acts as a disclosing agent. Cleaning the alginate impression:
- 24. How saliva helps in complete denture retention: Adhesion Adhesion is defined as the physical attraction of unlike molecules to one another. • It depends on: Close adaptation of denture. Size of denture-bearing area. Type of saliva. • Adhesion also takes place directly between the denture base and mucosa in case of xerostomia (lack of saliva), but this leads to ulcerations and abrasions in the mucosa
- 25. Cohesion • Cohesion is defined as the physical attraction of like molecules to one another. • This occurs within the film of saliva and aids in retention • Normal saliva is not very cohesive; hence, retention from mucosa interface is more dependent on adhesion and surface tension. • As viscosity of saliva increases, greater is the cohesion but very thick, mucous saliva can physically push the denture out, resulting in loss of retention
- 26. Interfacial surface tension Interfacial surface tension is defined as the tension or resistance to separation possessed by a film of liquid between two well adapted parallel surfaces . Interfacial surface tension is also dependent on existence of a liquid/air interface at the boundary of the liquid/solid contact. The external boundary of the mandibular denture is always filled (immersed) in saliva, thereby reducing the surface tension effect Hence, interfacial surface tension plays a significant role in retention of only the maxillary denture. Capillarity That quality or state, which because of surface tension causes elevation or depression of the surface of a liquid that is in contact with a solid. Capillarity causes the thin film of saliva to rise and increase its contact with the denture base and the mucosa. Close adaptation of the denture base to mucosa is important for capillarity to provide effective retention.
- 27. Denture Insertion and After Phase : • New dentures are often interpreted as foreign objects by the oral system. • This leads to stimulation of salivary glands to produce saliva. • On excessive salivation patient may complain of floating dentures. But this decreases over the weeks after denture insertion .
- 28. Denture Plaque Formation : Plaque formation is usually preceded by the adsorption of a pellicle onto the naked substratum. Pioneer species are Grampositive rods and cocci, particularly streptococci, whose dextran provides an anchor for secondary colonizers. Denture Stomatitis: A Plaque Mediated Disease The term describes a bright red inflammation in the oral mucosa in contact with the fitting surface of a denture usually the maxilla. Denture stomatitis is usually graded clinically in 3 types Type 1 – localized inflammation or pinpoint hyperemia Type 2 – diffuse erythema Type 3 – inflammatory papillary hyperplasia
- 29. Dental implantology: • Osseointegrated titanium implants installed in the oral cavity are exposed to the saliva and its microflora and are immediately colonized by non- virulent oral bacteria. If plaque is allowed to accumulate, this leads to inflammatory reactions in the adjacent tissues. • Similarly as on the tooth surface plaque on dental implants undergoes changes resulting in a more gram negative and anaerobic flora contemporary with the development of inflammatory reactions in the gingiva. • Peri-implantitis increases the risk of more virulent microorganisms becoming established and thereby the risk of failing implants.
- 30. The implant screw hole may become contaminated by blood and saliva during surgery, gingival forming, impression taking, and trial fittings The pH of saliva can affect in areas around dental implants. Corrosion occurs in implants due to changes in pH of saliva There are electrochemical reactions that occur in corrosion of metals. The salivary contamination affects the preload of implant prosthetic screws.
- 31. Xerostomia: “Dryness of the mouth due to lack of normal secretions of saliva” GPT 9 ETIOLOGY: DRUGS: • ANTIHISTAMINS • ANTIDEPRESSANTS • CALCIUM CHANNEL BLOCKERS PSYCHOLOGICAL: • ANXIETY • STRESS • DEPRESSION RADIATION THERAPY: Seen after Oral cancer and radiation therapy of head and neck. Systemic diseases: • Diabetes • Sjrogrens syndrome • AIDS • Parkinsons disease ETC. Salivary glands dysfunction: • Sialolithiasis • Aplasia of salivary glands • Surgical removal of glands • Inflammation Biological aging
- 32. Signs and symptoms: Dysphagia (difficulty in swallowing) Dysgeusia (alteration in taste) Halitosis (bad breadth) Burning sensation in the mouth Tongue tends to stick on the palate Reduced denture retention in denture wearers. Diagnosis: History taking Symptoms and Clinical examination Saxon test Saxon test: • Simple, reproducible, and low-cost test for xerostomia, which involves chewing on a folded sterile sponge for 2 minutes. • Saliva production is quantitated by weighing the sponge before and after chewing. • Normal control subjects produced greater than or equal to 2.75 gm of saliva in 2 minutes.
- 33. SYMPTOMATIC MANAGEMENT: Drinking liquids frequently, even during the night. Sugar-free chewing gums may increase salivary flow. Smoking, alcohol, and sugar intake must be avoided. Saliva substitutes and saliva stimulants (methylcellulose) could be used in severe cases. Tooth pastes, gels, and mouth rinses with fluoride should be used. Medication – capable of stimulating salivary glands- pilocarpine 5 – 10 mg, 3/4 times daily, administered 30 minutes before food
- 34. PROSTHODONTIC REHABLITATION IN XEROSTOMIA PATIENT: 1. Salivary reservoir 2. Application of palatal spacer and reservoir lid 3. Salivary sensors 4.Artificial salivary sprays on intaglio surface. Artificial salivary substitute Carboxymethylcellulose based Mucin based E.g. Wet mouth, Salix Salivart , Moi-stir • Reservoirs should be refilled by patients at regular intervals of 3-4 hrs
- 35. References : Guyton and Hall textbook of medical physiology 13th edition Grey’s anatomy 41st edition Boucher’s complete denture prosthodontics,13th edition Saliva in Prosthodontic Therapy – All You Need To Know! Smitha Annie Jacob, and Anoop Gopalakrishnan2 Gurkar H, Venkatesh OY, Somashekar JM, Gowda MH, Dwivedi M, Ningthoujam I. Prosthodontic management of xerostomic patient: a technical modification. Case Reports in Dentistry. 2016. Karthikeyan V, Chander NG, Anitha KV. A salivary sensor for the management of xerostomia in edentulous patients. The Journal of Prosthetic Dentistry. 2019;121(3):384-6.
Editor's Notes
- Salivary glands are compound, tubuloacinar exocrine glands whose ducts open into the oral cavity. They secrete saliva, a fluid that lubricates food to assist deglutition, moistens the buccal mucosa, which is important for speech, and provides an aqueous solvent necessary for taste and a fluid seal for sucking and suckling. Salivary glands also secrete digestive enzymes, e.g. salivary amylase, and antimicrobial agents, e.g. immunoglobulin A (IgA), lysozyme and lactoferrin, into saliva. Conditions in which there is a significant decrease in the production of saliva (xerostomia) may result in periodontal inflammation and dental caries. In edentulous patients, it is very important for the retention and comfort of the prosthesis. A comprehensive knowledge regarding saliva is essential for providing efficient prosthodontic treatment and after care.
- The primordial parotid gland starts to develop in the sixth embryonic week at the site of the eventual duct orifice near the angle of the stomodeum. Three stages are described in the development of the salivary glands. The first stage includes the anlage and the development of branched duct buds that are dichotomous. Two cell types are present: ciliary epithelial cells that line the lumen, and myoepithelial cells covering the external surface. A second stage includes early formation of lobules and canalization of the ducts. The third stage leads to further differentiation of the acinar cells and intercalated ducts with a reduction of the interstitial connective tissue.
- 5.8 cm in craniocaudal dimension and 3.4 cm in the ventrodorsal axis; situated below the external acoustic meatus, between the ramus of the mandible arteriorly and the sternocleidomastoid posteriorly. The gland overlaps these structures. Anteriorly, the gland also overlaps the masseter muscle. Medially lies the styloid process. Stensen‘s duct emerges from the anterior parotid gland, courses over the masseter muscle and buccal fat pad, and then turns medially, to pierce the buccinator muscle at the level of the second upper molar tooth
- one half the weight of the parotid gland It occupies most of the submandibular triangle of the neck, and the gland is folded around the dorsal free edge of the mylohyoid muscle. ;;;;;;Along its course, the duct makes an approximately 45-degree angle with both the sagittal and axial planes. As the duct courses upward, the lingual nerve winds around it,
- It lies above the mylohyoid, below the mucosa of the floor of the mouth, medial to the sublingual fossa of the mandible and lateral to the genioglossus
- (von Ebner's gland) occur only at the back of the tongue in the neighborhood of the taste-buds, their ducts opening for the most part into the fossæ of the vallate papillæ. These glands are racemose (clustered), the duct of each branching into several minute ducts, which end in alveoli, lined by a single layer of more or less columnar epithelium. Their secretion is of a watery nature, and probably assists in the distribution of the substance to be tasted over the taste area.
- The preganglionic fibres begin in the inferior salivatory nucleus; pass through the glossopharyngeal nerve, its tympanic branch, the tympanic plexus and the lesser petrosal nerve; and relay in the otic ganglion. The postganglionic fibres pass through the auriculotemporal nerve and reach the gland. Sympathetic nerves are vasomotor, and are derived from the plexus around the middle meningeal artery 3 Sensory nerves to the gland come from the auriculotemporal nerve, but the parotid fascia is innervated by the sensory fibres of the greater auricular nerve
- The salivatory nuclei are located approximately at the juncture of the medulla and pons and are excited by both taste and tactile stimuli from the tongue and other areas of the mouth and pharynx when a person smells or eats favorite foods, salivation is greater than when food that is disliked is smelled or eaten. Sympathetic stimulation can also increase salivation a slight amount—much less so than parasympathetic stimulation
- has approximately the same electrolyte composition as plasma. Thus, in initial saliva, osmolarity, Na+, K+, Cl−, and HCO3− concentrations are similar to those in plasma. The luminal membrane of the ductal cells contains three transporters: Na+-H+ exchange, Cl−-HCO3− exchange, and H+-K+exchange. The basolateral membrane contains the Na+-K+ ATPase and Cl− channels. The combined action of these transporters working together is absorption of Na+ and Cl− and secretion of K+ and HCO3−. Net absorption of Na+ and Cl− causes the Na+ and Cl−concentrations of saliva to become lower than their concentrations in plasma, and net secretion of K+ and HCO3− causes the K+ and HCO3−concentrations of saliva to become higher than those in plasma. Because more NaCl is absorbed than KHCO3 is secreted, there is net absorption of solute.
- The normal pH of saliva is 6 to 7, meaning that it is slightly acidic. bicarbonates, phosphates, and urea act to modulate pH and the buffering capacity of saliva; (2) macromolecule proteins and mucins serve to cleanse, aggregate, and/or attach oral microorganisms and contribute to dental plaque metabolism; (3) calcium, phosphate, and proteins work together as an antisolubility factor and modulate demineralization and remineralization; and (4) immunoglobulins, proteins, and enzymes provide antibacterial action.
- In xerostomia, denture will have poor retention and there is increased potential for soreness as lubricating action of saliva is lost. Excessive saliva will complicate impression making. The methods available presently for collection of whole saliva include draining, spitting, suction and swab method. 1]]]The subject is made to sit quietly with the head bent down and the mouth open to allow the saliva to drip passively from the lower lip into the graduated sterile tubes. Saliva collected by draining is without any stimulation and is more reliable. :2]]] Saliva is allowed to accumulate in the floor of the mouth and the subject spits out it into the preweighed or graduated test tube 3]]] : Saliva is allowed to accumulate in the floor of the mouth and aspirated continuously using micropipettes, syringes, saliva ejector or an aspirator 4]] : It is performed by introducing a synthetic gauze sponge, pre-weighed swab or cotton pad into the mouth, at the orifices of major salivary glands.
- Silicone impression materials are the best tolerated and least traumatic to the mucosa. Zinc oxide eugenol paste will adhere to and burn the mouth and materials such as plaster of paris will adhere to the mucosa and abrade it.
- These forces are found within the thin film of saliva that is present between the denture base and tissues. Saliva ‘wets’ the denture surface, to aid in retention. The oral mucosa has low surface tension and hence the saliva ‘wets’ it well, spreading out in a thin film. Denture base materials demonstrate less wettability than oral mucosa, with heat-cured resins showing better wetting than autopolymerized resins. But once coated with salivary pellicle, the surface tension of the denture base material decreases and contact increases. This is similar to trying to separate two glass plates with intervening liquid between them . If two plates with a fluid between them are immersed in the same fluid, then there is no interfacial surface tension and they can be separated easily.
- Also it is generally recognized that dentures have some effect on taste sensation. But the exact nature of sensory alteration and the role of saliva are not well understood. If good denture hygiene is not maintained, in the long run, saliva modulates the colonization of micro organisms in the pellicle leading to plaque formation which in turn leads to denture stomatitis.
- A complete or partial denture surface in contact with the palatal mucosa can provide an environment highly susceptible to plaque mediated disease called denture induced stomatitis (DIS). Types 2 and 3 have been associated with infection by Candida albicans. Patients are often not bothered by, or even aware of the condition, the initial alert being associated with more overt infection such as angular cheilitis, glossitis or rarely oral thrush
- The primary colonizers on oral implants are Streptococcus and Actinomyces species bound through receptors mediated by salivary glycoproteins in the oral biofilm.