2 Anatomical Considerations Two submandibularTwo ParotidTwo sublingual> 400 minor salivary glands
3 Minor salivary glands These lie just under mucosa. Distributed over lips, cheeks, palate, floor of mouth & retro-molar area.Also appear in upper aerodigestive tractContribute 10% of total salivary volume.
4 Sublingual Salivary glands This is the smallest of the major salivary glands.The almond shaped gland lies just deep to the floor of mouth mucosa between the mandible & Genioglossus muscle.It is bounded inferiorly by the Mylohyoid muscleSublingual gland has no true fascial capsule.It lacks a single dominant duct. Instead, it is drained by approximately 10 small ducts (the Ducts of Rivinus)
5 Submandibular GlandThis gland lies in the submandibular triangle formed by the anterior and posterior bellies of the Digastric muscle and the inferior margin of the mandible.The gland forms a ‘C’ around the anterior margin of the Mylohyoid muscle, which divides the gland into a superficial and deep lobe.
6 Submandibular Gland…… Wharton’s duct empties into the intraoral cavity lateral to the lingual frenulum on the anterior floor of mouth
7 Parotid Gland The parotid gland represents the largest salivary gland The following lists the boundaries of the parotid compartment:•Superior border – Zygoma•Posterior border – External Auditory Canal•Inferior border – Styloid Process, Styloid Process musculature, Internal Carotid Artery, Jugular Veins•Anterior border – a diagonal line drawn from the Zygomatic root to the EAC
8 Parotid Gland……80% of the gland overlies the Masseter and mandible. The remaining 20% of the gland (the retromandibular portionThis portion of the gland lies in the Prestyloid Compartment of the Parapharyngeal space
9 Parotid Gland……Stensen’s duct arises from the anterior border of the Parotid and parallels the Zygomatic arch, 1.5 cm inferior to the inferior margin of the arch.It runs superficial to the masseter muscle, then turns medially 90 degrees to pierce the Buccinator muscle at the level of the second maxillary molar where it opens onto the oral cavity.
10 Parotid Gland……Cranial Nerve VII divides it into 2 surgical zones (the superficial and deep lobes).After exiting the foramen, it turns laterally to enter the gland at its posterior margin.The nerve then branches at the Pes Anserinus (goose’s foot) approximately 1.3 cm from the stylomastoid foramen. The nerve then gives rise to 2 divisions:1)Temperofacial (upper)2)Cervicofacial (lower)
11 Parotid Gland…… 1)Temporal 2)Zygomatic 3)Buccal 4)Marginal Mandibular Followed by 5 terminal branches:1)Temporal2)Zygomatic3)Buccal4)Marginal Mandibular5)Cervical
12 Functions of saliva include the following: It has a cleansing action on the teethIt moistens and lubricates food during mastication and swallowingIt dissolves certain molecules so that food can be tastedIt begins the chemical digestion of starches through the action of amylase, which breaks down polysaccharides into disaccharides.The saliva from the parotid gland is a rather thin, watery fluid, but the saliva from the sublingual and the submandibular glands contains mucus and is much thicker.
13 Disorders of minor salivary Glands Extravasation CystsFollow traumaMSG with in lower lipVisible painful swellingSome resolve spontaneously or require surgery
14 Disorders of minor salivary Glands MSG tumours are rare but 90% are malignantCommon sites includeUpper lipPalateRetromolar regionsRare sites are nose/PNS/Pharynx
15 Disorders of minor salivary Glands Benign tumours present as painless slow growing swellings, overlying ulceration is rare.Malignant tumours have firmer consistency and have ulceration at later stage
16 Disorders of minor salivary Glands Benign tumors of palate < 1cm in size are removed by excisional biopsyWhen size larger than 1 cm prior incisional biopsy is doneMalignant tumors are managed by excision which may involve low-level or total maxillectomy and immediate reconstruction
17 Disorders of sublingual salivary Glands Problems are rareMinor mucous retention cystsPlunging ranula is a retention cyst that tunnels deepNearly all tumours are malignant
18 Plunging ranula Rare form of retention cyst May arise from SM/SL SG Mucous collects around glandPenetrates Mylohyoid muscle to enter neckSoft painless fluctuant dumb-bell shaped swellingSurgical excision via neck
19 Disorders of sublingual salivary Glands Tumours are rare90% are malignantWide excision and simultaneous neck dissection
20 Disorders of submandibular salivary Glands Acute sialadenitisViral (Mumps)Bacterial secondary to infectionMore CommonSecondary to obstructionPoor capacity to recoverDespite control with Abx chronicity follows and requires surgical excision
21 Chronic SialadenitisCommonly due to obstruction following stone formation80% salivary stones occur in SMSGHigh mucous contentAcute painful swelling rapidly precipitated by eating & resolves within 1-2 hoursEnlarged bimanually palpable SMGMarsuplisation/Excision
22 Tumors of Submandibular Salivary Glands Uncommon, slow growing, painlessOnly 50% are benignEven malignant tumours can be slow growingPain is not a reliable featureInvestigations:CT/MRIFNACNo open biopsy
23 Management Small & encased within capsule intracapsular excision Large benign tumors– suprahyoid excisionMalignant tumours require concomitant neck dissection
24 Disorders of parotid Glands Common causes of parotid swelling:MumpsAcute bacterial sialadenitis in dehydrated elderly patientsAcute bacterial parotitisObstructive parotitis: causes swelling at meal time
25 Parotid Tumours Most Common is pleomorphic adenoma (80-90%) Low grade Tumors like acinic cell carcinoma are not distinguishable from benignHigh grade Tumours grow rapidly, are often painful and have nodal metastasisCT/MRI are usefulFNAC better than open biopsyTx should be excised & not enucleated
27 Management Superficial parotidectomy most common procedure Radical parotidectomy is performed for patients clear histological evidence of high grade malignancy
28 Tumour like lesions Sialadenosis Diabetes Alcoholism Endocrine disordersPregnancyBulimia
29 Sjogren SyndromeAutoimmune condition causing progressive degeneration of salivary and lachrymal glandsThe oral aspects of primary Sjogren's syndrome consist of mucosal atrophy (80% to 95%), salivary gland enlargement approximately 30 %),The oral manifestations may include xerostomia with or without salivary gland enlargement, candidiasis, dental caries and taste dysfunction.
30 Investigations Sialometry Sialography Scintigraphy a radioactive tracer is given by vein that is subsequently taken up by the salivary glands and gradually eliminated within the salivary fluidSialochemistryUltrasonogramLabial or minor salivary gland biopsy
31 Management Symptomatic From the systemic drug treatment standpoint, immunosuppressive therapy in the form of corticosteroids or cytotoxic drugs have proven effective, in particular when symptoms are severe. A drug known as Plaquenil has also proven to be helpful in some cases with open questions remaining as to the role of alpha interferon and nonsteroidal anti-inflammatory drugs.