Salivary Gland Disorders By Abduaziz Alenezi Khaled Alsobhi Yahya Alfaqihi

1. Salivary Gland Disorders By Abduaziz Alenezi Khaled Alsobhi Yahya Alfaqihi

2. Objctives Type of Salivary Glands Anatomy of Salivary Glands Histology of Salivary Gland Component of salivary gland Functions of saliva Inflammatory Diseases of Salivary Gland Salivary Gland Masses

3. Type of Salivary Glands The Major Salivary Glands Parotid Submandibular Sublingual The Minor Salivary Glands numerous in the oral cavity and are named according to their locations: lingual, sublingual, palatal, labial, and glossopharyngeal.

4. Anatomy of Salivary Glands

5. Anatomy: Parotid Gland largest salivary gland composed mostly of serous acini lies in a deep hollow below the external auditory meatus, behind the ramus of the mandible. The facial nerve divides the gland into superficial and deep lobes The parotid duct emerges from the anterior border of the gland and passes forward over the lateral surface of the master enters the vestibule of the mouth upon a small papilla opposite the upper second molar tooth.

6. Anatomy: Submandibular Gland Lies beneath the lower border of the body of mandible and is divided into superficial and deep parts by the mylohyhoid muscle. The deep part of the gland lies beneath the mucous membrane of the mouth on the side of the tongue. The submandibular duct emerges form the anterior end of the deep part of the gland and runs forward beneath the mucous membrane of the mouth It opens into the mouth on a small papilla, which is situated at the side of the frenulum of the toungue.

7. Anatomy: Sublingual Gland The sublingual gland lies beneath the mucous membrane (sublingual fold) of the floor of the mouth, close to the frenulum of the tongue. It has both serous and mucous acini, with the latter predominating The sublingual ducts (8 to 20 in number) open into the mouth on the summit of the sublingual fold.

11. Nerve Supply  Parotid Gland Parasympthetic secretomotor supply arises from the glossopharyngeal nerve. The nerves reach the gland via the tympanic branch, the lesser petrosal nerve, the otic ganglion, and the auriculotemporal nerve. Submandibular Gland Parasympathetic secremotor supply is from the facial nerve via the chorda tympani and the submandibular ganglion. The postganglionic fibers pass directly to the gland. Sublingual Gland Parasympathetic secretomotor supply is from the facial nerve via the chorda tympani and the submandibular ganglion. Postgaglionic fibers pass directly to the gland. 

12. Histology of Salivary Gland Salivary glands produce saliva, a watery mixture of enzymes and mucus. The enzymes and the mucus are produced by two distinct cell types, called serous cells and mucous cells. Release of saliva is facilitated by contraction of myoepithelial cells.

14. Serous cells are specialized to secrete an enzyme solution. Examples include serous cells of the salivary glands, exocrine cells of the pancreas. Serous cells of the pancreas and the salivary glands are typically organized into secretory units called acini. Cells which are specialized to secrete mucus are called mucous cells. Examples in the GI system include secretory cells of the salivary glands, esophageal glands and stomach surface. These cells are typically organized into tubular secretory units.

15. Myoepithelial cells are contractile epithelial cells which forcibly express the contents of a gland. Although myoepithelial cells function like smooth muscle, they are typically located within a glandular epithelium, between the secretory cells and the basement membrane. Each myoepithelial cell has long cytoplasmic processes which wrap around a secretory unit. contraction of the myoepithelial processes can squeeze secretory product from the secretory unit into its duct.

16. Histologic picture of salivary gland under microscope

17. Component of salivary gland sublingual glands – found underneath the tongue parotid glands – at the sides of the mouth just in front of the ears submandibular - under the floor of the mouth, close to the mandible

18. Component of salivary gland parotid glands produce a serous, watery secretion submaxillary (mandibular) glands produce a mixed serous and mucous secretion sublingual glands secrete a saliva that is predominantly mucous in character

19. salivary gland functions The salivary gland functions are to maintain oral and dental hygiene, prepare food for mastication, taste, and deglutition, and begin carbohydrate digestion with amylase. In addition, they indirectly regulate body hydration because if you’re dehydrated, you’ll likely have a dry mouth, and you’ll want to drink more.

20. Functions of saliva 1-Moistening dry foods to aid swallowing 2-Providing a medium for dissolved and suspended food materials that chemically stimulate taste buds 3-Buffering of the contents of the oral cavity through its high concentration of bicarbonate ion

21. Functions of saliva 4-Digestion of carbohydrates by the digestive enzyme alpha-amylase 5-Controlling the bacterial flora because of the presence of the antibacterial enzyme lysozyme 6-Source of calcium and phosphate ions essential for normal tooth maintenance

22. Inflammatory Diseases Viral infection: Mumps Acute Bacterial Infection Chronic or Recurrent Infections Autoimmune Diseases - Sjogren's Syndrome

23. Viral - Mumps  Mumps is one of the commonly acquired viral diseases of childhood between 5-9year. A member of the paramyxovirus family , closely related to parainfluenza viruses The virus infects epithelial cells of respiratory tract Signs and symptoms Prodrome of fever, malaise, and headache may occur Painful swelling of one or both parotid glands with erythema of Stenson's duct orifice. Ingestion of sour liquids increases pain. Complications may occur due to involvement of other organs meningitis Hearing Loss Encephalitis Pancreatitis Prevention: by mumps vaccine (at age 15-24 months and at age 4-6 years or before junior high school 12 year of age .

26. Acute Bacterial Infection  Etiology Stasis, secondary to obstruction, decreased flow or dehydration predispose to bacterial infection by members from the oral flora: Staphylococcus aureus

27. Staphylococcus aureus is a gram-positive bacteria Under the microscope they appear round (cocci), and form in grape-like clusters (staphyl is Greek for bunch of grapes). Cultural characters on agar plates: It appears as large, round golden-yellow (which is where the name aureus comes from) colonies, with beta-haemolysis of blood agar. Facultative anaerobes. Important cell wall components and antigens include: Peptidoglycan Teichoic acid Protein A

28. Staphylococci can produce disease (pathogenesis) by their ability to multiply and invade tissues and also through the production of extracellular enzymes and toxins which include: Coagulase Haemolysins Exfoliative toxin

29. Cont, Signs and Symptoms Pain, tenderness and swelling with increased pain on eating. Orifice of duct is red and swollen, and massage of the gland may express pus. Treatment Antibiotics Warm compresses to relieve obstruction and pain. Promote drainage by Massage If condition is unresponsive or progressive after above, surgical drainage is indicated. In the parotid gland, care must be taken to avoid the facial nerve.

30. Chronic or Recurrent Infections  Etiology - Usually related to scarring and inflammation of the duct and/or parenchyma from prior infections May also be due to stones Signs and Symptoms: as in acute infection Treatment Conservative treatment as for acute infection In refractory disease, surgical excision is indicated

31. Autoimmune Diseases - Sjogren's Syndrome  Etiology: a collagen vascular disease Signs and Symptoms –kerato-conjunctivitis sicca, xerostomia, and a connective tissue disorder, such as rheumatoid arthritis. Enlargement of salivary and lacrimal glands, often with recurrent sialoadenitis Diagnosis – biopsy of salivary glands, usually the lower lip, shows lymphoreticular hyperplasia Treatment Treat recurrent infection May develop a superimposed malignancy. Therefore, if a mass appears, surgical excision is needed.

32. Salivary Gland Masses Etiology Inflammatory scarring or focal obstruction, Inflammatory lymph node enlargement, scalp or external ear infection, etc. Metastatic involvement of nodes Neoplasm Benign: 75-80% of all parotid tumors are benign Benign mixed tumor 65% of parotid neoplasms Warthin's tumor Lymphangioma, hemangioma Malignant - 20% of all parotid tumors are malignant. Submandibular and minor salivary gland tumors have increasing percentage of malignancy, i.e., the smaller the gland, the greater the likelihood of malignancy. Mucoepidermoid carcinoma Adenoid cystic carcinoma - associated with high propensity for nerve invasion Squamous cell carcinoma

33. Cont, Diagnosis Careful examination of scalp, ear and face for infection or malignant lesion Palpation of other lymph nodes Persistent salivary gland mass should be assumed to be neoplastic unless proven otherwise Minimum biopsy of parotid mass is a superficial parotidectomy Submandibular masses require excision of gland Minor salivary gland masses require excision with a margin of surrounding normal tissue

34. Treatment - Most salivary gland tumors require surgical excision of involved gland with or without post operative radiotherapy depending on the histology of the tumor and extent of disease