Introduction to salivary pathology
The salivary glands are divided into two types: the main salivary glands and the accessory salivary glands. They can be the site of lithiatic, infectious, or tumoral pathologies, which we will treat separately.
In this chapter we will see generalities with a diagnostic approach suitable for salivary pathology.
- Reminders:
- Anatomical reminders: The salivary glands are clinically divided into major (main) glands and minor (accessory) glands.
- Major (main) salivary glands : paired and symmetrical, we distinguish:
- Parotid gland:
Represents the largest gland, located in the parotid lodge, weighs approximately 25g, bilobed with a superficial and deep lobe.
Its excretory duct, called “stenon”, starts from the gland then travels through the cheek wall to open onto the mucosa opposite the second upper molar.
Crossing from depth to surface by:
🡺 The external carotid artery.
🡺 The internal jugular vein.
🡺 The auriculotemporal nerve (from V3, responsible for the secretory innervation of the gland).
🡺 The infra and extra glandular lymph nodes which drain into the internal jugular chain.
🡺 The facial nerve which enters the gland, dividing it into 2 lobes.
- Submandibular or submandibular gland :
Unilobed, occupies the submandibular compartment, located on the lateral part of the suprahyoid region.
Salivary secretion is drained by the Wharton duct which crosses the floor of the mouth to open at the level of a papilla located a few millimeters from the lingual frenulum.
The vascular connections of the gland are with the facial artery and vein, the lingual vessels.
- Sublingual gland:
Located in the floor of the mouth, in front of and outside the submandibular compartment.
Its drainage is multi-channel (15 to 30 channels), the largest being the canal of
“Rivinus”.
Its vascularization is provided by the lingual artery and vein. Innervation is provided by the lingual nerve.
- Minor (accessory) salivary glands: These are small glandular formations scattered under the mucosa of the entire oral cavity, except for the gums and the anterior part of the bony palate.
- Histo-embryological reminders:
- They develop from epithelial buds of ectoblastic (major GS), mesoblastic (minor GS) or mixed origin.
- The parotid and submandibular glands : 6th week of IVF
- The sublingual gland: 9th week .
- GSAs from the 12th week of VIU.
Organized into lobes made up of several lobules , themselves formed of several acini .
The saliva secreted by the acini is collected by a network of canals differentiated into an intercalated canal for the acini and a striated canal for the lobule, which finally join the excretory canals.
Depending on the type of acini:
The parotids are called serous glands ;
The submandibular and sublingual glands are mixed , with a predominance of serous acini
for the submandibular glands and mucous acini for the sublingual glands. The accessory glands are called mixed glands .
- Physiological reminders:
- Control of salivary secretion:
The stimulation of salivary secretion is essentially under the control of the sympathetic and parasympathetic autonomic nervous system (parasympathetic effects are predominant)
This stimulation is activated by taste and touch sensations in the oral cavity and by smell, via the hypothalamus.
- Composition of saliva:
- Saliva is a complex mixture of secretions produced by the salivary glands, food residues, gingival fluid, and desquamated epithelial cells.
- Its pH varies between 6.7 and 8.5 in humans.
- It is composed of 99% water . 1% of organic and inorganic constituents . Role of saliva:
- Digestive role 🡺 by facilitating the formation of the food bolus, and swallowing, as well as its role in the physiology of taste;
- Protective role 🡺 of the mucous membrane and teeth against drying and irritation. Salivary flow also ensures mechanical cleaning of the mucous membrane and dental surfaces;
- Diagnostic approach:
- Anamnesis: allows you to specify:
- Age , gender .
- The symptoms of the call: pain, swelling, inflammatory manifestations…
- Date and methods of onset of the pathology , its sudden or progressive nature, unilateral or bilateral, related or not to meals.
- Medical-surgical and locoregional history: trauma, certain general illnesses (diabetes) as well as certain therapies which have proven their impact on salivary flow (radiotherapy)
- Subjective description by the patient of the character of the saliva: scant or abundant saliva, liquid or thick, unpleasant taste or not).
- We should also look for a feeling of dry mouth or eyes, inflammatory joint pain, and dermatological lesions, as these can point us towards a systemic inflammatory condition: Sjogren’s syndrome, connective tissue disease, sarcoidosis, etc.
- Clinical examination:
- Exo-oral examination:
- Inspection: morphology of the region, condition of the integuments, facial expressions, facial asymmetry.
- Palpation: Volume, consistency, mobility in relation to the skin and deep planes, manual expression of the gland (parotid, submandibular).
Palpation should be exo- and endo-buccal, bidigital, comparative and carried out in conjunction with examination of saliva at the orifice of the excretory duct.
- Intraoral examination:
Quantitative assessment of saliva:
- The sugar cube test;
- Saliva expressible at the ostium of a major gland.
- The time for a droplet of saliva to reappear on the wiped mucosa.
Qualitative assessment of saliva:
- Appearance of saliva: stringy or viscous, clear or cloudy.
- Measurement of salivary pH (colorimetric method = litmus paper).
These tests will be carried out remotely (at least 30 min) 🡺 sleep, meals, prolonged speech, tooth brushing, medication intake.
- Additional examinations:
- Salivary Gland Imaging:
- Shots without preparation:
- Salivary Gland Imaging:
- Standard images: looking for a radiopaque salivary stone .
Standard images can be useful for detecting stones, calcifications of inflammatory or tumor pathologies.
We distinguish: The occlusal bite for the submandibular gland, the OPT can highlight radiopaque stones.
At the level of the accessory glands: a retro-jugal or retro-labial dental film may be useful.
- Ultrasound:
Allows the diagnosis of stones > 2mm in diameter and helps in the diagnosis between solid tumor and liquid tumor, it can also show global hypertrophy of the gland.
Pathological images can be of two types: a hyperechoic image (calcification) or hypoechoic (expanding process, lymph nodes, infection)
- Sialendoscopy: allows the diagnosis and treatment of ductal lesions (stones < 2mm)
III.1.2. Shots with preparation:
- Sialography:
The oldest technique for exploring the salivary glands. It involves injecting a contrast agent (fat-soluble or water-soluble) into the gland to make it radiopaque to X-rays.
It provides information on the anatomopathological aspect of the parenchyma and salivary ducts. Furthermore, it allows the functional value of the gland to be assessed.
It is an easy-to-perform technique that requires inexpensive and readily available investigation equipment.
- Normal sialogram:
- Ductal image of the main duct and efferent ducts.
- A parenchymal cloud.
- Pathological sialogram:
- Canal anomalies:
- Dilation :
Lithiasis: the rigid-looking dilation is located or predominates around and upstream of the stone; the lithiasis is usually unilateral.
- Shrinkage – interruption :
Neighboring inflammatory swelling, Ductal or periductal tumor.
- Parenchymal anomalies: lacunar images, amputation images.
- Computed tomography (CT): allows the objectification of tumor and non-tumor conditions of the main glands.
- Magnetic Resonance Imaging (MRI):
MRI is currently the standard examination for tumors of the salivary gland parenchyma, particularly the parotid gland.
- Scintigraphy:
Know the functional value of GS: Gives an image of secretion at rest and after stimulation.
- Anatomopathological examination:
- Biopsy:
Find its best indication 🡺 systemic conditions 🡺 sarcoidosis, SGS … Site 🡺 GS accessories on the inner side of the lower lip.
In case of neoplastic glands 🡺 Biopsy contraindicated 🡺 Possible cancerous spread
- Cyto-puncture :
Interesting 🡺 negligible risk of neoplastic dissemination
- Differential diagnosis:
- Bilateral non-inflammatory swellings:
- Sarcoidosis:
The association of bilateral, painless, rapidly developing parotid hypertrophy and uveitis (uveoparotitis) results in Heerfordt syndrome, typical of sarcoidosis; it is often accompanied by facial paralysis and possibly other manifestations: cutaneous, bone, pulmonary, lymph node, visceral. The evolution of this parotid disease is often rapidly favorable.
- Dry eye syndromes:
They combine diffuse bilateral parotid swelling, dry eyes (xerophthalmia) and dry mouth (xerostomia).
- Unilateral non-inflammatory swellings (tumor pathology):
Benign swelling logically presents in an isolated, asymptomatic manner, with a regular and mobile appearance, whereas the presence of adenopathies, nerve paralysis (VII for the parotid), trismus, or pain should suggest a malignant tumor.
- Inflammatory swelling:
- Cellulitis: should be considered and ruled out given the absence of dental etiology and also the presence of a free groove between the inner face of the cheek and the external alveolar table.
Conclusion :
The search for salivary pathologies begins with a thorough clinical diagnostic examination which includes the history of the patient’s local and general pathologies, a questioning, then a clinical examination proper, exo and endo-buccal.
This clinical examination must be confirmed by carefully targeted additional examinations.
Introduction to salivary pathology
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Misaligned teeth can cause speech problems.
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Antiseptic mouthwashes reduce bacteria that cause infections.
Decayed baby teeth must be treated to avoid complications.
An electric toothbrush cleans more effectively than a manual one.