Salivary Glands Chapter 1 PDF
Document Details
King Salman International University
Dr/Emad Sarhan, MD
Tags
Summary
This chapter details the anatomy and physiology of salivary glands, encompassing the parotid and submandibular glands, and their associated structures and functions. It provides a detailed description of the gland's structure, location, and blood supply as well as their nerve supply.
Full Transcript
King Salman International University Faculty of Medicine Department of Clinical Medical Sciences CHAPTER 2: Salivary glands...
King Salman International University Faculty of Medicine Department of Clinical Medical Sciences CHAPTER 2: Salivary glands Nerve supply is from autonomic nervous system, By Dr/Emad Sarhan, MD o Parasympathetic is secretomotor from Asst. Professor of Surgery auriculotemporal nerve (from mandibular ANATOMY division of trigeminal nerve) o Sympathetic is vasomotor from plexus around the external carotid artery. Structures within the parotid gland from deep to superficial ▪ External carotid artery, maxillary artery, superficial temporal artery, posterior auricular artery ▪ Retromandibular vein (by maxillary and superficial temporal veins) ▪ Facial nerve with its branches Parotid Gland (Para—around, otis—ear) ▪ It is the largest of the salivary glands, situated below the acoustic meatus between the ramus of the mandible and sternomastoid muscle. ▪ The deep cervical fascia splits to form a capsule (parotid capsule) to enclose the gland ( deficient at the upper part) ▪ The superficial layer is thickened and adherent to the gland. Parts of the Parotid Gland ▪ Superficial part (80%): lies over the posterior part of the ramus of the mandible. ▪ Deep part (20%): lies behind the mandible and medial pterygoid muscle; in relation to mastoid Submandibular Salivary Gland and styloid process. ▪ Accessory parotid is a prolongation of the gland along the parotid duct. Parotid (Stensen’s) duct ▪ It is 2-3 mm in diameter ▪ 5 cm in length ▪ Begins behind the angle of the mandible ▪ Runs over the the masseter muscle ▪ Passes through the buccinator muscle, ▪ Opens into the oral mucosa opposite to the crown It is a ‘J’ shaped salivary gland situated in the of upper second molar tooth. anterior part of the digastric triangle. Facial nerve emerges from the stylomastoid foramen** and passes around the neck of the mandible then divided into temporofacial and cervicofacial branches Branches : o Temporal (auricularis anterior and superior part of frontalis), Parts o Zygomatic (frontalis and orbicularis oculi), ▪ Superficial part: Lies in submandibular triangle, o Buccal (buccinator, OO, elevators of the lip) superficial to mylohyoid and hyoglossus muscles, o Mandibular (lower lip muscles) between the two bellies of digastric muscle. o Cervical (platysma). ▪ Deep part is in the floor of the mouth and deep to Blood supply is from external carotid artery; and the mylohyoid. venous drainage is by EJV King Salman International University Faculty of Medicine Department of Clinical Medical Sciences Submandibular (Wharton’s) duct : ▪ Gland drains directly into mucosa or through a ▪ (5 cm), emerges from the deep part of the gland, duct which drains into submandibular duct. This enters the floor of the mouth, on the summit of duct is called as Bartholin duct. papilla beside the frenulum of the tongue. Sialography Lingual nerve and submandibular ganglion : Attached to upper pole of the gland. Hypoglossal nerve is deep to the gland. Facial artery emerges from under surface of the stylohyoid muscle, enters the gland from posterior and deep surface, reaching its lateral surface crossing Indications the lower border of mandible to enter the face. o Salivary fistulas. Venous drainage is to anterior facial vein. o Sialectasis. Nerve supply: Branches from the submandibular o Congenital conditions. ganglion. o Extraglandular masses. Physiology o Parotid duct stones. ▪ Resting salivary flow usually arises from the Findings submandibular salivary gland. ▪ Narrowing (Stricture) ▪ Sialorrhoea is increased salivary flow often seen ▪ Grape like cluster appearance (Sialectasis) due to drugs, in cerebral palsy, physically ▪ Dilatations handicapped person, children, and psychiatry ▪ Communications (Fistulas) patients. ▪ Mass lesions ▪ Xerostomia is decreased salivary flow. It is seen in Precautions postmenopausal women, depression, ▪ Sialography should never be performed in acute dehydration, use of antidepressant drugs; inflammation. anticholinergic drugs, Sjogren’s syndrome, ▪ Only one ml of dye should be injected, if more and radiotherapy to head and neck region. dye is injected it causes extravasation and chemical sialadenitis. Acute Sialadenitis Aetiology ▪ Stasis o Dehydration and reduced salivary flow o Obstruction of duct by stone r stricture ▪ Lack of oral hygiene ▪ After major surgery, radiotherapy for oral malignancies ▪ Infection o Bacterial usually staphylococci o Viral as Mumps (common in parotid) Minor Salivary Glands Presentation ▪ There are around 450 minor salivary glands ▪ distributed in lips, cheeks, palate, and floor of the mouth. ▪ may be present in oropharynx, larynx, trachea and paranasal sinuses. ▪ They contribute to 10% of total salivary volume. Sublingual glands are minor salivary glands one on each side; located in 1- Acute Submandibular sialadenitis the anterior aspect of the floor of the mouth in ▪ Fever and toxemia relation to mucosa, mylohyoid muscle, body of the ▪ Pain, swelling, tenderness is seen in mandible near mental symphysis. submandibular region and floor of the mouth. ▪ Duct is inflamed and swollen. King Salman International University Faculty of Medicine Department of Clinical Medical Sciences 2- Parotid abscess (acute suppurative parotitis) ▪ Calculi are more common in submandibular gland, ▪ Pyrexia, malaise, pain and trismus. because ▪ Red, tender, warm, well-localised, firm swelling is o The gland secretion is viscous, seen in the parotid region and contains more calcium ▪ Tender lymph nodes are palpable in the neck. o Opening of duct lies in the floor of mouth ▪ Features of bacteraemia are present in severe (obstructed by food particles ) cases. o Its drainage is non-dependent, causing ▪ Pus or cloudy turbid saliva may be expressed stasis ( duct ascends upward) from the parotid duct opening. Aetiology Investigations ▪ Stasis ▪ U/S of the neck and parotid region. ▪ Infection provides ▪ Pus collected from duct orifice is sent for culture o Nucleus and sensitivity. o Exudate for sticking food particles ▪ Needle aspiration from the abscess is done to o Change PH of saliva confirm the formation of pus Complications ▪ Sialogram is contraindicated in acute phase, as it ▪ Sialadenitis will cause retrograde infection leading into ▪ Sialectasis bacteraemia. ▪ fistula Note: In suppurative parotitis patient may develop Chronic sialadenitis severe laryngeal or pharyngeal oedema and may ▪ Common after partial obstruction of require steroids, tracheostomy and critical care. submandibular gland duct or due to stones in Treatment submandibular gland or hilum proximal to the ▪ Hot fomentations and analgesics and Antibiotics level of crossing of the lingual nerve over the duct ▪ When it is severely tender and localised, drainage Presentation is done under G/A. ▪ Pus is drained through Blair’s incision and sent for C/S. ▪ Proper hydration, mouth wash using povidone iodine/potassium permanganate solutions, nutrition. Causes of acute parotitis ▪ Viral—Mumps, parainfluenza self limiting painful Symptoms : parotid enlargement with fever ▪ Pain and swelling below the mandible that ▪ Bacterial: Staphylococcus aureus increase with meals ▪ Endemic parotitis : bilateral parotid enlargement Signs: occur in parasiric infestation and protein ▪ Salivary colic** which can be induced by meals, malnutrition lemon juice. ▪ Allergic, HIV infection, Radiotherapy, Specific ▪ Salivary secretion is more during mastication infections like syphilis causing increase in gland size. ▪ Sjogren’s syndrome often causes bilateral ▪ Firm, tender swelling is palpable bidigitally and parotitis can’t be rolled over the lower border of the SALIVARY CALCULUS mandible ▪ When stone is in the duct, it is palpable in the floor of the mouth with features of inflammation in the duct. Pus exudes through the duct orifice. ▪ Irritation of the lingual nerve, which is in very close proximity to submandibular salivary duct, causes referred pain tongue (lingual colic) ▪ 80% Submandibular. Differential Diagnosis ▪ 80% Radio-opaque. ▪ Submandibular lymphadenitis. ▪ It is commonly calcium phosphate and calcium ▪ Salivary neoplasm. carbonate stones. King Salman International University Faculty of Medicine Department of Clinical Medical Sciences SIALECTASIS ▪ Aseptic dilatation of salivary ductules causing grape like (cluster like) dilatations. ▪ common in parotids often bilateral with destruction of parenchyma of gland with stenosis and cyst formation in the ductules resulting in Investigations repeated sialadenitis ▪ Intra oral X-ray (dental occlusion films) to see Aetiology radiopaque stones. ▪ Childhood type: familial ▪ FNAC of the gland to rule out other pathology. ▪ Adult type ▪ Sialography o 2ry to Sjogren syndrome Treatment o Occupations that requires chronic increase in ▪ If the stone is in the duct, removal of the stone is the intraoral pressure done intraorally Clinical picture ▪ If stone is in the gland, excision of submandibular ▪ Presents as painless smooth, soft, fluctuant, gland or superficial conservative parotidectomy nontransilluminating swelling which increases in size during mastication. ▪ Repeated attacks of infection Sialogram is diagnostic (grape-cluster like dilatations). Treatment is essentially conservative but excision of glang can be done in complicated cases Parotid fistula Complications of Surgery 1. Haemorrhage. 2. Infection. 3. Injury to marginal mandibular nerve, lingual nerve, and hypoglossal nerve. 4. Injury to nerve to mylohyoid causing anaesthesia over submental skin. 5. Fistula ▪ Parotid fistula may arise from parotid gland or Rule of 2 in submandibular salivary gland duct or ductules. ▪ 2 parts divided by mylohyoid muscle ▪ It may be internal or external fistula. ▪ 2 condition affect it—tumour and stone ▪ Fistula from the duct has profuse discharge. ▪ 2 superficial nerves—cervical and mandibular Fistula from the gland often shows only minimal branch of facial nerves discharge. ▪ 2 deep nerves—lingual and hypoglossal nerves Causes ▪ Incision—2-4 cm below the mandible ▪ After drainage or ruptured of parotid abscess ▪ Ligate facial artery at 2 places ▪ After superficial parotidectomy. SIALOSIS ▪ After biopsy or Trauma. ▪ It is an enlargement of the salivary gland due to ▪ Malignancy fatty infiltration, as a result of various metabolic Clinical Features causes like diabetes, acromegaly, obesity, liver ▪ Discharging fistula in the parotid region and disease, alcoholism, idiopathic, drug-induced discharge is more during eating. (sympathomimetics, carbimazole, thiouracil). ▪ Tenderness , induration and Trismus. Clinical features: Bilateral diffuse enlargement of Diagnosis parotids, which is smooth, firm, nontender. ▪ Sialography to find out the origin of the fistula Treatment: The cause is treated. ▪ CT fistulogram. ▪ Discharge study. ▪ MRI. King Salman International University Faculty of Medicine Department of Clinical Medical Sciences Treatment Mikulicz disease: Variant of Sjogren’s syndrome** ▪ Anticholinergics - hyoscine bromide (probanthine). Triad ▪ Radiotherapy. 1. Symmetrical and progressive enlargement of all ▪ Often exploration of fistula is required and removal salivary glands of the fistula track 2. Narrowing of palpebral fissures due to enlargement ▪ Repair or reinsertion of the duct into the mucosa. of the lacrimal glands ▪ If still persists, auriculotemporal nerve is cut. 3. Dryness of the mouth ▪ If there is stenosis at the orifice of the Stenson’s duct, papillotomy. Salivary Neoplasms ▪ Total conservative parotidectomy is done in failed Incidence cases. ▪ 80 % of salivary neoplasms are in the parotids of SJÖGREN’S SYNDROME which ▪ Autoimmune disease causing progressive o 80% are benign (80% of these are pleomorphic destruction of salivary and lacrimal glands, leading adenomas) to keratoconjuctivitis sicca (dry eyes), and ▪ 10-15 % of salivary tumours are in the xerostomia (dry mouth). submandibular salivary gland Types: Primary and Secondary. o 50% are benign (95% of these are pleomorphic Primary Sjogren’s Syndrome: ▪ Severe dry mouth andSevere dry eyes. adenomas) ▪ Widespread dysfunction of exocrine glands. ▪ 5-10 % of salivary neoplasms are in the minor ▪ Incidence of developing lymphomas is high. salivary glands ▪ There is no association of connective tissue o only 10% are benign. disorders. Secondary Sjogren’s Syndrome: ▪ Dry mouth, Dry eyes with association of connective tissue disorders like o Primary biliary cirrhosis (near 100%). o SLE (30%). o Rheumatoid arthritis (RA) (15%). Clinical Features ▪ Female to male ratio is 10 : 1, in middle aged females who present with dry eyes, dry mouth, enlarged tender.parotids and enlarged lacrimal glands. Lymphoepithelial tumours ▪ Superadded infections of the mouth, Candida Benign :It is 5% of all benign salivary tumours albicans is common (Godwin’s tumour). Investigations Malignant: It is rare tumour occurs in parotid and 1. Autoantibody estimation: RF, antinuclear factor, submandibular glands (ESKIMOMA). salivary duct antibody. 2. Sialography. Pleomorphic Adenoma (Mixed Salivary Tumour) 3. Estimation of salivary flow. ▪ Commonest of the salivary gland tumour (80%) 4. Slit lamp test of eyes. ▪ More common in parotids (80%). 5. Schirmer test – to detect lack of lacrimal secretion. ▪ It is Mesenchymal, Myoepithelial and duct reserve 6. FNAC of parotids and lacrimal glands. cell origin. 7. 99Technetium pertechnetate scan for gland ▪ Grossly : lobulated encapsulated & contains function. cartilages, cystic spaces, solid tissues. Treatment: It is conservative. ▪ Histologically it shows: Epithelial cells, 1. Artificial tears. Myoepithelial cells, Mucoid material with 2. Artificial saliva. myxomatous changes and 3. Frequent drinking of water. Cartilages/pseudocartilages 4. Treat the cause. ▪ Even though it is capsulated, tumour may come out as pseudopods and may extend beyond the main limit of the tumour tissue. King Salman International University Faculty of Medicine Department of Clinical Medical Sciences ▪ Commonly it involves superficial lobe or o Involvement of neck lymph node superficial and deep lobe together but sometimes Complications only deep lobe is involved and then it presents as ▪ Recurrence: (5-50%) swelling in the lateral wall of the pharynx, soft ▪ Malignancy.{10% in long duration (15 or more palate years) tumours} Clinical Features Investigations ▪ FNAC is very important and diagnostic. ▪ CT scan and MRI to know the status of deep lobe, local extension and spread. Note: Incision biopsy of parotid tumour is contraindicated as chances of seedling and recurrence are high and also Treatment Surgery: ▪ If only superficial lobe is involved: Consevative superficial parotidectomy is done ▪ If both lobes are involved, then total conservative parotidectomy is done ▪ Enucleation is avoided as the recurrence rate is high. Adenolymphoma (Warthin’s Tumour, Papillary Cystadenolymphomatosum) ▪ It is a misnomer. It is not malignant, it is not lymphoma. ▪ It is a benign tumour that occurs only in parotid, ▪ 1:1 male to female ratio and occurs in any age usually in the lower pole. group. ▪ It is said to be due to trapping of jugular lymph ▪ Usually unilateral single painless, smooth, firm sacs in parotid during developmental period. lobulated, mobile swelling in front of the parotid ▪ It composed of double layer of columnar with positive curtain sign ** epithelium, with papillary projections into cystic ▪ The ear lobule is lifted with obliteration of spaces with lymphoid tissues in the stroma. retromandibular groove is common. Clinical Features ▪ Deviation of uvula and pharyngeal wall towards ▪ Its incidence is 10% and 10% bilateral. midline in case of deep lobe tumour ▪ It is common in males – 4:1. ▪ Facial nerve is not involved. ▪ Common in old people – 60 years. Long-standing pleomorphic adenoma may turn into ▪ Usually involves only superficial lobe but it may carcinoma (carcinoma in ex. pleomorphic adenoma). also be multicentric. Its features are: ▪ It presents as a slow growing, smooth, soft, cystic, o Recent increase in size fluctuant swelling, in the lower pole, often o Pain and nodularity bilateral and is nontender. o Involvement of skin, ulceration Investigations o Involvement of masseter ▪ Adenolymphoma produces a “hot spot” in o Involvement of facial nerve:Lower facial nerve 99Technetium scan** palsy** King Salman International University Faculty of Medicine Department of Clinical Medical Sciences ▪ FNAC. Adenolymphoma does not turn into Submandibular salivary gland tumours malignancy. Benign tumours: Treatment ▪ Commonly pleomorphic adenomas, are smooth, ▪ Consevative Superficial parotidectomy. firm or hard, bidigitally palpable, without ▪ Enculeation can be done involving adjacent muscles or nerve sor mandible MUCOEPIDERMOID TUMOUR bone. ▪ It is the commonest malignant salivary gland ▪ Diagnosis is by FNAC and CT scan. tumour (in major salivary glands). ▪ Excision of both superficial and deep lobes of the ▪ It contains malignant epidermoid and mucus gland is done. secreting cells. Malignant tumours ▪ Facial nerve involvement is late in mucoepidermoid carcinoma of parotid. Types Low grade: mucus cells mainly. High grade: epidermoid cells mainly. Clinical Features ▪ They are hard, nodular, ▪ fixed to skin, muscles, hypoglossal nerve and mandible. General Features of Malignant Salivary Tumours 1. Pain and anaesthesia in the skin and mucosa 2. Rapid rate of growth ▪ Swelling in the salivary (parotid or submandibular) 3. Fixation, Irregular, Nodular, Ill defined edge, region, slowly increasing in size, eventually Hard in Consistency attaining a large size, which is hard, nodular, often 4. Resorption of adjacent bone with involvement of skin and lymph nodes 5. Infiltration of skin, muscles, vessels, nerves (facial Treatment nerve in parotid or hypoglossal nerve in ▪ Removal of the gland with postoperative submandibular salivary gland) radiotherapy 6. Involvement of jaw and masticatory muscle ACINIC CELL TUMOUR 7. Blood spread when occurs, commonly to lungs ▪ It is a rare, slow growing tumour that occurs almost always in parotid and is composed of cells alike serous acini. It is more common in women. It occurs in adult and elderly. ▪ It can involve facial nerve or neck lymph nodes. ▪ Clinically it is of variable consistency with soft and cystic areas. ▪ It is low grade malignant tumour. Adenoid Cystic Carcinoma (10% Of Salivary Tumours) ▪ It is common in submandibular and minor salivary glands. ▪ It consists of myoepithelial cells and duct epithelial cells ** ▪ It involves facial nerve very early, spreads through the perineural sheath and infiltrates into the Investigations for malignant salivary gland tumora\s perineural tissues over a long distance, more ▪ FNAC. proximally. ▪ CT scan to see the deep lobe of the parotid: the ▪ It also invades periosteum and bone medulla early involvement of bone, extension into the base of and spreads extensively. the skull, relation of tumour to vessels ▪ Prognosis is poor. ▪ Blood grouping and cross matching; required ▪ Radical parotidectomy and radical radiotherapy is amount of blood is kept ready. the treatment of choice King Salman International University Faculty of Medicine Department of Clinical Medical Sciences ▪ FNAC of lymph node. ▪ It is 10% of salivary tumours. ▪ MRI shows better soft tissue definition than CT ▪ It is common in ( palate (40%), lip, cheek, SL scan. Sialogram is not useful in assessment of glands) tumour. ▪ 10% are benign—commonly pleomorphic adenomas. ▪ 90% are malignant:commonly adenoid cystic carcinomas. ▪ They present as swelling with ulcer over the summit. Investigations 1. Incision biopsy. 2. CT Scan. 3. X-ray maxilla. 4. FNAC of lymph node. Treatment ▪ Wide excision often with palatal excision or maxillectomy is done ▪ Reconstruction by dental plates, skin grafting, or flaps are done. Treatment of Malignant salivary gland tumors ▪ Lymph node block dissection of the neck is done if In parotid: involved. ▪ Radical parotidectomy is done which includes ▪ Excision with primary closure is done for benign removal of both lobes of parotid, soft tissues, part tumours. of the mandible with facial nerve. PAROTID LYMPHOMA ▪ Facial nerve is reconstructed using greater ▪ Can occur from the lymph nodes in the gland or auricular nerve, or sural nerve. from parotid parenchyma. ▪ Often lateral tarsorrhaphy or temporal sling ▪ Occur in HIV patients; lymphoepithelial diseases reconstruction is done. and in Sjogren’s syndrome. ▪ If lymph nodes are involved: radical neck ▪ Common in elderly. dissection is done.** ▪ May be confined to parotid gland or may involve In submandibular salivary gland: other nodes in neck, mediastinum. ▪ Wide excision, with removal of adjacent muscle, ▪ When it is confined to parotid total parotidectomy soft tissues and mandible. with radiotherapy and later chemotherapy is the ▪ If lymph nodes are involved, block dissection of treatment. neck is done. ▪ When many other nodes are involved Postoperative external radiotherapy chemotherapy is the choice therapy. ▪ It is given to reduce the chances of relapse. Frey’s Syndrome (Auriculo-temporal Syndrome) ▪ It is given in all carcinomas, but more useful in (Gustatory Sweating) adenoid cystic and squamous cell carcinomas. ▪ Occurs in 10% of cases. Radiotherapy is delayed for 6 weeks after surgery if ▪ It is due to injury to the auriculo temporal nerve, nerve grafting is done. wherein post-ganglionic parasympathetic fibres from the otic ganglion become united to sympathetic nerves Chemotherpy from the superior cervical ganglion (Pseudosynapsis). ▪ Drugs given here depends on tumour type. ▪ Auriculotemporal nerve has got two branches. Minor salivary gland tumours ▪ Auricular branch supplies external acoustic meatus, surface of tympanic membrane, skin of auricle above external acoustic meatus. ▪ Temporal branch supplies hairy skin of the temple. Sweating and hyperaesthesia occurs in this area of skin. Causes ▪ Surgeries or accidental injuries to the parotid or temporomandibular joint King Salman International University Faculty of Medicine Department of Clinical Medical Sciences Clinical Features Clinical Features ▪ Flushing, sweating, pain and hyperaesthesia in the Inability to close the eye-lid. skin over the face innervated by the Difficulty in blowing and clenching. auriculotemporal nerve, whenever salivation is Drooping of the angle of the mouth. stimulated (i.e. during mastication). Obliteration of naso-labial fold. ▪ Involved skin is painted with iodine and dried. Dry Loss of forehead wrinkles. starch applied over this area will become blue due Wide palpebral fissure. to more sweat in the area in Frey’s syndrome— Epiphora. Starch iodine test. Treatment of Frey’s syndrome Treatment ▪ Initially conservative and reassurance** Nerve grafting using greater auricular nerve, sural ▪ Occasionally (10%) they require surgical division nerve, lateral cutaneous nerve of thigh or hypoglossal of the tympanic branch of the glossopharyngeal nerve. nerve below the round window of middle ear, (i.e. Suspension of angle of mouth to zygomatic bone intratympanic parasympathetic (Jacobsen nerve) using temporal fascia sling. neurectomy). Lateral tarsorrhaphy—to prevent corneal ulceration. ▪ Injection of botulinum toxin to the affected skin Medial canthus reconstruction—to reduce epiphora. ▪ Antiperspirants like aluminium chloride Cross facial nerve transplantation from opposite side using its insignificant branches. Dynamic neuro-vascular muscle graft. Upper lid gold weights to protect cornea ▪ Parasympathetic and sympathetic supply of the parotid gland. Otic ganglion located just below the foramen ovale close to mandibular nerve relays the parasympathetic supply from glossopharyngeal nerve through tympanic branch, tympanic plexus in middle ear and then lesser superficial petrosal nerve. Post-ganglionic fibres run in auriculotemporal nerve along with Thank you unrelayed sympathetic fibres from middle meningeal plexus. Emad Sarhan FACIAL NERVE INJURY (Lower motor nerve lesion, surgically related) Causes Trauma Surgery—parotidectomy, drainage of parotid abscess Compression of facial nerve—Bell’s palsy. Incidence of temporary/transient facial nerve palsy after parotidectomy is 30%. Recovery occurs usually in 12 weeks.