PATHOLOGY OF THE SALIVARY GLANDS

I- Fundamental notions:

The salivary glands are divided into:

• major or main salivary glands 
• accessory or minor salivary glands

I.1 Anatomy

  I.1.1 Parotid Gland:

It is a prismatic, triangular-shaped gland, weighing approximately 25g and yellowish-grey in colour. It is made up of two lobes:

• a superficial lobe spread over the Masseter and the ascending branch
• a deep retromandibular lobe

Its excretory canal is the stenon: it is approximately 4cm long with a diameter of 

3mm the parotid gland presents to describe a masseteric extension which is sometimes isolated on  

 then calls it: accessory parotid.

Innervation is provided by the facial nerve and the auriculotemporal branch.

Venous drainage is provided by the external jugular vein.

The arterial system is represented by the external carotid. (Internal maxillary and superficial temporal.)

For lymphatic drainage, it is represented by numerous chains including the internal jugular and the spinal. 

   I.1.2 Submaxillary gland:

The submaxillary or submandibular gland is a gland of about 7g located in a bony and musculoaponeurotic excavation. The excretory duct is the Wharton canal, about 7cm long with a diameter of 3mm. Along its path, the Wharton describes two portions, one of which is horizontal and goes from the excretory orifice along the floor of the mouth. Opposite the 1st ^molar , it crosses the lingual nerve, describes a curve and runs vertically.

The warthon opens through the umbilical orifice.

The submaxilla has a mylohyoid extension which comes into contact with the sublingual. 

Innervation is provided by the lingual nerve and the chorda tympani. 

The venous system flows into the facial vein.

Arterial vascularization is provided by the facial and submental arteries. The lymphatics flow into the internal jugular. 

 I.1.3 Sublingual gland:

 Weighs about 3g, about 3cm long. It occupies the alveolo-lingual groove.

It is made up of a cluster of glands with as many ducts, the most important of which are the Rivinus and the Bartholin duct. The rest of the ducts , called Walther ducts, open into the sublingual eminence. 

• Nerve: sublingual + chorda tympani. 
• Veins: deep lingual and ranine vein 
• Arteries: sublingual
• Lymphatics open into the internal jugular.

 

I.1.4 Accessory salivary glands (ASG):

These glands are scattered and line the entire oral mucosa except at the level of the gum and the anterior region of the palate

     * the GSAs surrounding the Steno’s ostium are called “molar glands”

      * lingual GSAs:

     -Von Ebner dorsals

     -Weber marginals

 

 1.2. Embryology:

The gs develop from epithelial buds of epiblastic, entoblastic or mixed origin. The parotid and s/max buds appear at the 6th week, the sublingual buds at the 9th week and the accessory gs at the 12th week.

1.3 Histology:

The salivary glands are made up of a set of lobes; each lobe is made up of lobules and each lobule is made up of acini.

There are 3 types of acini: serous (parotid + gsa), mucous (sublingual), mixed (submaxillary)
*ACINI :   cluster of secretory cells grouped around a collecting duct called the intercalated duct, itself surrounded by myoepithelial cells whose cytoplasmic extensions contain myofibrils responsible for the expulsion of saliva.

 *Different types of cells:

• Zymogen cells  secrete water, electrolytes, and proteins (mainly enzymes) into the lumen of the acini.
• Mucus cells  secrete mucus = glycoproteins of variable molecular weight, can aggregate together => gel in contact with water: viscous and stringy nature of saliva.
• Myoepithelial cells  are not secretory cells, but are cells that, when stimulated, contract, promoting the secretion of saliva into the acini.

*Excretory ducts

They are lined by rectangular type cells =  ductal cells . They are surrounded by myoepithelial cells.

  I.4. Physiology

 I.4.1 Physiology of salivary secretion:

The accessory salivary glands continuously secrete a fluid that moistens the CB

The main GS secrete only under the influence of mechanical, thermal, olfactory or psychic stimuli

The formation of saliva occurs first at the level of the acini; it is isotonic saliva with respect to the plasma. At this stage, it is primary saliva. At the level of the striated canal, this saliva will undergo physicochemical modifications and will become saliva II area. 

   

 I.4.2 Physicochemical characteristics of saliva

• Volume: approximately 750 ml /24 hours

• Appearance: watery (parotid), stringy (s/max), very viscous (sibling)
• pH varies depending on age and location e.g.:
  • pH stenon=5.5 
  • pH back of the tongue = 6.5 to 7 
• Composition of saliva:

Water: 95%

Electrolytes: Na+, K+, Cl- …

Organic substances:

       Exogenous: drugs, toxins

       Endogenous: 

               -enzymes (alpha amylase++)

               -Lysozyme

               -Lactoferrin

               -Mucins: hydrolization of mucus

               -Immunoglobulins: IgM, IgG..

               -endocrine factors (EGF, NGF)

• Role of saliva:

• In digestion its action is minimal: essentially for carbohydrates via α-amylase.
• It is important in oral, dental, and gingival hygiene. It has a mechanical cleansing action: thanks to its viscous character. 
• Role in maintaining the trophicity of dental enamel. It has anti-infectious power: alkaline pH, immunoglobulins. 
• It is important for tasting: it dissolves molecules to better reach the taste buds. 
• It is an essential lubricant for speaking and swallowing. 
• It is important for tissue renewal via tissue growth factors secreted by the salivary glands.

 

 II/ EXPLORATIONS OF THE GS

II.1 The interrogation

swelling: mode of appearance + evolution

lockjaw

dysphagia

salivary secretion disorders

general pathology

occupation

II.2 The clinical examination:

• Swelling:

   topography

   clinical characteristics

• Salivary ostia: gaping, swollen, invisible….
• Saliva test:

 1- quantity : * manual expression of each gland then inspection at the level of the ostium in search of a jet of saliva

        *time for reappearance of palatal and labial saliva droplets after drying

        * sugar cube test: a size 4 sugar cube melts in 3 minutes in a seated subject who does not swallow

2-Quality:

• appearance: serous, mucoid, purulent
• pH: away from meals, exercise, speech.

    Back of the tongue N= 6.5 to 7

    Steno N = 5.5 to 6

    warthon N= 6

Palpation of the salivary glands should be bimanual, carefully looking for any irregularities. 

II.3 Paraclinical examinations:

II.3.1 Radiological examinations:

 

a\ shots without preparation:

   used mainly in the search for a radiopaque stone or as the first step in sialography

B\ sialography :

It is the opacification of a parotid or s\max gland after catheterization of the duct

contrast agents can be oily (lipiodol) or water-soluble (telebrix)

Interpretation:
    In normal state

Parotid: the parenchyma forms an image of a homogeneous, low-density cloud. The ductal system is regularly opacified.

s/max: in profile the parenchyma gives a roughly oval image, +dense and –homogeneous /parotid

C – cone beam imaging:

Cone beam imaging produces images with great sharpness and beautiful 3D reconstructions.

The medial portion of the parotid is also better distinguished than in sialography.

The cone beam is particularly indicated in cases of non-lithiatic retention syndrome of the parotid gland. It individualizes the sixth-order glandular ducts. It is not or only slightly

altered by dental artifacts.

D/Computerized tomography :

The scanner allows us to assess the extent of a pathological process affecting the salivary glands and in the case of an invasive tumor, its contribution is essential to specify its limits and its extension towards neighboring elements and deep structures.

It also allows monitoring after treatment (radiotherapy or surgery)

Sialo-CT or sialo-scanner is a variant of CT with preparation and injection of contrast product, however the quality of the information obtained has not allowed it to be imposed as a substitute for sialography.

E-ultrasound

It is an integral part of the salivary gland exploration assessment and constitutes an atraumatic, inexpensive and easy to perform first-line examination. Ultrasound exploration easily makes the differential diagnosis of salivary gland tumors. It also allows the detection of stones larger than 2 mm in diameter.

 

 F/ MRI

MRI has the advantage over CT scanning of better differentiation of soft tissues and avoidance of irradiation. MRI is indicated mainly in the assessment of tumor recurrences. 

Technical improvement has led to the promotion of a new concept, called sialo MRI. This non-irradiating technique, without catheterization of the salivary ducts or injection, allows satisfactory canal exploration even if the resolution is lower than in sialography.

  

g/ Scintigraphy

Technetium99 remains the most suitable radioisotope.

Allows a morphological and functional assessment of the gs.

Indicated in cases of tumor, salivary secretion disorders, dry syndromes. 

 

h/Sialendoscopy:

It is a minimally invasive technique that allows the diagnosis and treatment of canal lesions using an endoscope consisting of a probe equipped with optical fibers that allow visual monitoring of the contents of the canal.

II.3.2 Salivary gland biopsy

• The BGSA proposed by CHISHOLM and MASSON in 1968 is a simple procedure which consists of an incision of a few mm of the lower lip allowing to obtain several glandular lobules. Biopsy of the main glands is strongly discouraged. The BGSA is of great use in the diagnosis of a whole series of pathologies.

 

^4th year  course

Dr. S. Benaouf

Salivary stones

1. INTRODUCTION :

Salivary gland stones are characterized by the predominance of submaxillary (submandibular) stones, due to the anatomical and physiological conditions specific to this gland.

3 hypotheses are retained to explain this predominance: 

  1° Hypothesis related to diagnostic errors. Many parotid stones have remained unrecognized. The arrival of endoscopy has made it possible to diagnose parotid stones that were inaccessible by X-ray.

2° Anatomical hypothesis: the Warthon canal being longer, its ostium narrower and the saliva having to flow from bottom to top are elements in favor of salivary stasis.

3° Physicochemical hypothesis: s/max saliva is richer in mucins and thicker, promoting calcium precipitation. 

   The complications of lithiasis are of two types: infectious and mechanical.

Terminology:

• Sialitis, sialadenitis: inflammation of the gland

Ex: parotitis, submaxillitis, sublingualitis 

• Sialodochitis: inflammation of the excretory duct

Ex: warthonite or warthon sialodochite 

2- structure and mechanism of formation of the stone:

 The stone often has a rough surface. It can be oval or spherical, often with a groove running longitudinally (like a date stone). 

To explain the formation of the stone, we mention:

• Salivary stasis
• Precipitation of mineral salts
• Crystallization from a microbial nucleus 

Salivary calculus is composed mainly of Ca salts. It develops from a central core, the organic matrix, around which successive layers of mineral salts and organic elements are deposited (25% ORG-75% MIN)

2. submandibular lithiasis:

3.1  Mechanical complications:

  These complications are related to salivary retention (retention syndrome) and most often appear after a meal:

*Garel’s hernia: which is a swelling of the gland below the basilar rim and in front of the mandibular angle

*Morestin’s colic : severe pain radiating to the tongue, floor and even the ear.

These signs last a few moments and then disappear after the flow of a saliva stream.

3.2 Infectious complications:

They occur later than mechanical accidents and are not punctuated by meals.

They vary depending on their topography and their evolutionary mode. They can occur:

• At the canal level: 

 1/ Whartonite or warthon sialodochite:

Swelling of the salivary ridge, the ostium is red with pus discharge. The pain is accompanied by dysphagia.

General signs are moderate

• Around the canal

2/ Periwhartonitis or floor abscess:

A real abscess of the floor

exacerbation of signs with high fever (39.5)

the floor of the mouth is raised with persistence of the gingivolingual sulcus 

• At the gland level:

3/ Submaxillitis (sialadenitis): 

 Gradually, the infection spreads to the gland. There will be a suprahyoid swelling that can extend towards the neck. Intraorally, the floor of the mouth is raised unilaterally.

The ostium is red and turgid with emission of pus at the orifice.

*paraclinical examinations:

Rx without preparation:

Occlusal, panoramic image 

The calculation appears as a projected opaque radio image.

TDM :

 very useful for the detection of stones and even the state of the glandular parenchyma 

sialography: 

Is not systematic 

 The calculus appears as a lacuna surrounded by product with upstream canal dilation. 

3.3 Differential diagnosis:

• At the latency stage:

-non-glandular calcifications: cementoma, apex, ganglion 

calcified, calcified angioma, tonsillar calcification

– glandular calcifications: calcinosis 

• At the stage of complications:

*mechanical :

 -salivary megaducts: bilateral dilation, absence of stones

 -salivary retention syndrome by:

         dyskinesias

         anatomical

*infectious:

-periwarthonitis: cellulite, sublingualitis 

-s/maxillitis: adenophlegmon, chronic non-lithiatic s/maxillitis (children ++)

*pseudotumoral :

pelvic-oral tumors, benign or malignant salivary tumors

3.4 Treatment:

* medical treatment:

ATB, ATG, AI, antispasmodic Tièmonium (increase canal diameter),

    sialogogues:

    parasympathomimetics: pilocarpine (Salage®)+++

                                         Jaborandi tincture

                                         Eseridine (Généserine®)

   sympathomimetics:DH E (Seglor®)

   choleretics: anetholtrithione (Sulfarlem® s 25)

*surgical treatment:

Transmucosal stone removal:

  in case of previous calculation it is the classic “Wharton size” 

s/maxillectomy:

very posterior or intraglandular calculus 

Extracorporeal lithotripsy may be proposed in preparation for excision of a large stone. 

4. Parotid lithiasis:

4.1 Positive diagnosis:

is based on clinical signs which are comparable to those described for s/max but- revealing:

    * mechanical complications:

• salivary colic: located in front of the ear of moderate intensity 
• salivary hernia: preauricular jugal swelling 
• palpation only reveals anterior and sufficiently large stones 

(Ramus prevents posterior bidigital palpation)

* infectious complications:
dominate the symptoms.

• In the Stenonite channel: 

pain in front of the ear, moderate fever, purulent red ostium, cloudy saliva

• around the Peristenonite canal:

Jugal abscess, rare, jugal swelling, earache, trismus, general signs sometimes marked require hospitalization

• upstream of the lithiasic parotitis canal: 

most often reveals parotid lithiasis, preauricular swelling, skin redness with induration on palpation, sometimes discharge of pus from the inflammatory ostium, satellite adenopathy, fever, headaches, exceptional PF.

4.2 Paraclinical examinations:

• Rx without preparation: 

small stones difficult to highlight, tangential image of the cheek, endobuccal film, open mouth panoramic

• sialography:

shows the image of gap, blockage, dilation 

4.3 Differential diagnosis:

• Latency stage: 

Extraparotid calcifications no longer pose diagnostic problems with sufficiently thin CT slices

• Stage of complications

    -retention syndrome without lithiasis:

    – acute non-lithiatic parotitis

    – chronic recurrent parotitis 

    – mumps parotitis

4.4 Treatment:

• Surgery being less practiced/ at most medical treatment remains necessary
• Ablation of the stone by the intraoral route remains reserved for large anterior stones 
• Conservative parotidectomy should be reserved for treatment failures and inaccessible intraglandular stones.  

5-Other stones:

• Sublingual lithiasis:

Simulates Warthon lithiasis but the x-ray shows a stone outside the Warthon canal path 

• Lithiasis of the accessory salivary glands:

You should think about it when faced with a small painful swelling located on the inner side of the lips.

Inflammatory pathology of the salivary glands

I – Introduction:

Etiopathogenesis : In normal conditions, saliva is sterile in the acini. Infection can be:

*ascending of buccal origin

*hematogenous or septicemic

*break-in into the gland of a nearby infection

All favored by:

 salivary stasis, immunosuppression,

salivary enzyme dysfunction.

1. Sialadenitis

1.1 Viral sialadenitis

               a/ mumps:

– the most common viral infection of the salivary glands. It is caused by an RNA paramyxovirus. It is transmitted by direct contact or saliva droplets

-it causes small epidemics in winter/spring

-it affects children and young adults++

-affects both sexes but complications are more serious in boys (orchitis = risk of sterility).

• Typical form

After an incubation phase of 18 to 21 days, the short invasion phase appears (24 to 36 hours) characterized by high contagiousness: fever-bradycardia-malaise. 

clinically: parotid swelling raising the earlobe with otalgia especially when eating++.

dry mouth with redness of the ostium 

 These signs require the patient to be isolated.

bilateralization in 2 to 3 days, inconstant oropharyngeal enanthema, rare clear saliva never purulent

• Misleading forms :

 Unilateral or submandibular forms, Associated salivary and lacrimal forms  

Differential diagnosis:

• First episode of chronic bacterial parotitis in a child.
• 1st infectious episode of lithiasis
• Allergic or toxic parotitis
• nutritional sialomegaly.

Positive diagnosis:

Clinical diagnosis can be confirmed by culture of the virus from saliva

Treatment:

Avoidance, rest, ATG, NSAIDs.

Vaccine prophylaxis (MMR) 

 

 1.2 Bacterial sialadenitis:

1-Sialadenitis due to common germs:

 a/ acute parotitis with common pyogenic bacteria :

clinical:

•  sudden or gradual onset
•  significant local and general inflammatory signs (swelling-earache-trismus-fever-possible facial paralysis)
•  red and turgid ostium with the presence of pus or purulent saliva.
• risk of fistulization in the absence of treatment or canal drainage 

treatment :

• Preventive treatment: 

 fight against salivary stasis

• Curative treatment: antibiotic therapy depending on the germs involved

 incision and drainage in case of suppuration

 washing of the gland through the duct.

b/ acute suppurative submaxillitis not caused by stones in adults:

• Exceptional 
• simulates a floor phlegmon
• Ultrasound allows us to distinguish between what is glandular and what is extraglandular. 
• Ultrasound: shows multiple hypoechoic images in a non-homogeneous parenchyma 

sialography: small round cavitary images +/- appended to dilated canals, pathognomonic appearance of a “flowering tree” or “shot pellet” image. 

c/ recurrent bacterial parotitis in children:

1st episode around 5 years old often confused with mumps followed by a 2nd episode after a few months The clinic allows to distinguish it from a recurrence of mumps. The onset is sudden and acute marked by the appearance after a meal, most often, of a firm and painful swelling the examination of the ostium shows mucoid or purulent saliva all occurs in a context of moderate alteration of the general condition, dominated by an asthenia which can precede the disorders by a few dozen hours. 

 e/ chronic or recurrent bacterial parotitis in adults:

• Acute episodes (swelling + parotid pain) generally progressing spontaneously to healing within 3 to 10 days
• rare fistulization
• Rocking seat but may remain unilateral, bilateral location argues for general cause 
• sialography: large drops of lipiodol with regular ductal dilations

Treatment

• ATB continued even after clinical recovery
• washing with lipiodol or antibiotics (penicillin).

 2. Sialadenitis due to specific germs:
syphilitic sialadenitis has practically disappeared while tuberculous sialadenitis is still current.

a/ tuberculous sialadenitis :

• affects the parotid gland twice as much as the submaxillary gland.
• pretragic or s/max cold nodule. In the absence of treatment, other nodules may appear and end up softening with fistulization in the skin
• thermal curve + telethorax + IDR + culture allow diagnosis.

 Additional examinations

• Ultrasound: several nodules with a center that is +/- anechoic (caseation)
• Sialography: impression image on inflammatory parenchyma
• Echodopplers: allow hypervascularization of the lacuna to be visualized.

Treatment

Uses anti-tuberculosis drugs for 6 to 12 months followed or not by surgical treatment (parotidectomy, submaxillectomy).

b/ paratuberculous sialadenitis:

• Atypical mycobacterial adenitis is described in very young children
• the clinical picture is very close to a parotid or s/max TBC
• only culture allows us to distinguish them 
• favorable prognosis: complete recovery in a few weeks.

1.5 Sublingualitis :

• Their etiology is still poorly defined
• two semiological aspects can be observed,

– one properly sublingual and it is a unilateral lifting of the ridge +/- nodular not exceeding the Warthon canal in front with clear saliva

      – The other aspect shares the same semiology with s/maxillites.

• Sialography: 

 The normal appearance of the submaxilla constitutes a diagnostic argument for sublingualitis.

Differential diagnosis:

   *cylindrome

   *infected mucocele

   *lipoma

   *chronic cellulite.

Treatment :

 Almost always surgical.

2 Sialodochites:

• Chronic canal infection is mainly caused by megacanals or stones.
• Acute ductal infection only exists as an initial stage of parotitis or ascending bacterial maxillitis. 

PATHOLOGY OF THE SALIVARY GLANDS

  Baby teeth must be cared for to prevent future problems.
Periodontal disease can cause loosening.
Removable dentures restore chewing function.
In-office fluoride strengthens tooth enamel.
Yellowed teeth can be treated with professional whitening.
Dental abscesses often require antibiotic treatment.
An electric toothbrush cleans more effectively than a manual one.
 

PATHOLOGY OF THE SALIVARY GLANDS