88. Salivary glands

Question 1

List the four major salivary glands

Answer 1

1. Parotid
2. Mandibular
3. Sublingual
4. Zygomatic

Question 2

The parotid gland is superficial to the …

Answer 2

Vertical ear canal and is triangular shaped

Question 3

The parotid gland is bordered:
1. Rostrally by…
2. Caudally by…
3. Ventrally by…
4. Superficially by..

Answer 3

1. Rostrally by the masseter muscle and the temporomandibular joint
2. Caudally by the sternomastoideus and cleidocervicalis muscles
3. Ventrally by the mandibular salivary gland
4. Superficially by the parotidoauricularis and platysma muscles

Question 4

The parotid gland is covered by a thin capsule that blends with deeper surrounding structures. Name 7 of these structures.

The intimate association of the parotid capsule and gland with surrounding structures creates a challenging dissection for complete removal of the parotid salivary gland.

Answer 4

1. Facial nerve
2. Maxillary artery
3. Temporal artery
4. Internal maxiallary vein
5. External acoustic meatus
6. Stylomastoid foramen

The stylomastoid foramen transmits the facial nerve, and the stylomastoid artery.

Question 5

The parotid duct is formed by two or three converging ductules on the ventrorostral border of the gland.
1. Where does it travel?
2. Where does is open?

Answer 5

It travels over the lateral aspect and ventral third of the masseter muscle and opens into the oral cavity through a small papilla at the level of the upper fourth premolar.

Question 6

Where is an accessory parotid gland found?

Accessory parotid gland in the form of glandular lobules

Answer 6

Dorsal to the parotid duct.

Question 7

Where does the accessory parotid gland tissue empty into ?

Answer 7

Directly into the main parotid duct through several small communications.

Question 8

What is the arterial supply to the parotid gland?

Answer 8

Parotid artery a branch of the external carotid artery.

Several other small branches from surrounding arteries also contribute to its perfusion.

Question 9

Describe the location to identify the parotid artery

Answer 9

ID: the medial aspect of the parotid gland in the region *ventral *to the external ear canal

Question 10

Name the venous return from the parotid gland

Answer 10

Superficial temporal and great auricular veins

Question 11

The majority of the lymphatic flow from the parotid gland is directed toward which two lymph nodes.

Answer 11

1. Parotid lymph node
2. Medial retropharyngeal lymph node

Question 12

Describe the location of the zygomatic gland

In reference to the globe and zygomatic arch

Answer 12

Located in the periorbital area just **ventral and rostrolateral **to the globe and medial to the zygomatic arch

Question 13

How many major and minor ducts come from the zygomatic gland into the oral cavity?

Answer 13

One major
Four minor

Question 14

Where does the zygomatic gland major duct open into the oral cavity?

Answer 14

Caudolateral aspect of the last upper molar

Parotid (yellow arrow) and zygomatic (red arrow) salivary duct openings dorsal to the left maxillary fourth premolar and first molar in a dog. These papillae are more prominent than in most canine patients.

Question 15

Typically the zygomatic papilla is approximately 1 cm caudal to the parotid salivary papilla.
True or false?

Answer 15

True

Question 16

What artery supplies the zygomatic gland?

Answer 16

A branch of the infraorbital artery

Question 17

Name the vein draining the zygomatic salivary gland

Answer 17

Deep facial vein

Question 18

Name lymph node that zygomatic gland drain

Answer 18

Medial retropharyngeal lymph node

Question 19

Mandibular and sublingual salivary gland are seperated by the sublingual muscle. True or false?

Answer 19

False

Intimately associated and thus considered anatomically as a pair.

These two glands share a common capsule and can initially look like a single gland

Question 20

The mandibular salivary gland can be palpated.
True or false?

Answer 20

True

Large, palpable gland located caudomedial to the angle of the mandible

Question 21

Describe the location of the mandibular salivary gland

In relation to veins, lymph nodes and anatomic land marks

Answer 21

It lies on the medial aspect of the **linguofacial and maxillary vein junction. The mandibular lymph nodes lie on its ventral surface and the medial retropharyngeal lymph node** and** larynx** on its **medial **surface.

Its cranial border abuts the primary portion of the sublingual salivary gland.

Question 22

Where does the mandibular salivary duct exit on the gland?

Answer 22

On the glands medial surface.

Question 23

Describe the course of the mandibular salivary duct

Answer 23

Continues rostrally, medial to the sublingual salivary gland and horizontal ramus of the mandible. Under the oral mucosa, it travels between the styloglossus and mylohyoideus muscles until it exits into the oral cavity

oral cavity: sublingual caruncle lateral to the lingual frenulum

Question 24

Where does the mandibular salivary gland enter into the oral cavity?

Answer 24

Sublingual caruncle lateral to the lingual frenulum

anatomic locations of papillae for the left zygomatic (a), parotid (b), and mandibular (inset; c) salivary glands

Question 25

Name the major blood supply to the mandibular salivary gland

Answer 25

**Glandular branch** of the **facial artery** ## Footnote Other small arteries and veins may be present

Question 26

Name the venous drainage from the mandibular salivary gland

Answer 26

Branch of the **lingual vein** ## Footnote Other small arteries and veins may be present

Question 27

Name the lymph nodes the mandibular salivary gland drains to

Answer 27

Retropharyngeal lymph nodes

Question 28

The sublingual salivary gland is composed of monostomatic and polystomatic portions. True or false? ## Footnote Monostomatic glands deliver saliva to a distant site through a singular duct, whereas polystomatic glands produce saliva locally through multiple openings adjacent to the saliva-producing glands

Answer 28

True

Question 29

Which portion of the sublingual salivary gland is found in the capsule shared by the mandibular salivary gland?

Answer 29

Largest and most caudal component of the monostomatic portion ## Footnote It has a large portion that abuts the mandibular salivary gland and tapers to a triangular shape rostrally

Question 30

Describe the sublingual salivary gland location external to the capsule

Answer 30

The gland continues rostrally in *close association* with the *mandibular duct* but is **packaged in loose clusters** of glandular tissue deep to the **digastricus** and **mylohyoideus muscles**

Question 31

Sublingual salivary tissue caudal to the **lingual nerve** empties into the ........duct and is considered a ..........stomatic salivary gland.

Answer 31

Sublingual salivary tissue caudal to the lingual nerve empties into the **sublingual** duct and is considered a **monostomatic** salivary gland.

Question 32

Sublingual salivary gland: The polystomatic salivary tissue consists of small clusters of glandular tissue **rostral** to the **lingual nerve** that typically empty **directly into the oral cavity**. True or false?

Answer 32

True

Question 33

The major sublingual salivary duct courses where?

Answer 33

Alongside the mandibular duct

Question 34

The major sublingual salivary duct usually exits where?

Answer 34

At the **sublingual caruncle** just caudal to the mandibular duct.

Question 35

The monostomatic portion of the sublingual salivary gland receive blood supply from where?

Answer 35

The **glandular branch** of the **facial artery**

Question 36

The polystomatic portion of the sublingual salivary gland receive blood supply from where?

Answer 36

The **sublingual branch** of the **lingual artery**

Question 37

Name sublingual salivary gland venous drainage

Answer 37

Satellite veins

Question 38

Lymphatics from the sublingual salivary gland drain to the?

Answer 38

**Medial retropharyngeal** lymph nodes

Question 39

What are minor salivary glands?

Answer 39

Small collections of salivary tissue surrounding the oral cavity that drain their secretions directly into the oral cavity to keep it moist

Question 40

Name SIX minor salivary glands

Answer 40

1. Buccal 2. Labial 3. Lingual 4. Tonsillar 5. Palatine 6. Molar ## Footnote Salivary gland disease is rarely reported with the minor salivary glands.

Question 41

Open-mouth view in an anaesthetised cat. What is circled?

Answer 41

The membranous molar pad (circled) containing the molar gland, lingual to the molar tooth

Question 42

Name functions of saliva | (six)

Answer 42

* Lubricate ingesta - facilitate packaging of a food bolus for its passage down the oesophagus * Thermoregulation (evaporative cooling) * Oral cavity cleansing * Buffering of weak acids * Reduction of oral bacterial growth * Protection of surface epithelium in the oral cavity

Question 43

Salivary α-amylase in dogs and cats plays a significant role in carbohydrate digestion. True or false?

Answer 43

False. Unlike in other species, salivary α-amylase in dogs and cats does not play a significant role in carbohydrate digestion.

Question 44

Describe the pathway of saliva from the **acinus** to the **major excretory ducts**

Answer 44

Saliva travels from the acinus to the** intercalated ducts**, then to the **intralobular ducts**, **interlobular ducts**, **lobular ducts**, and finally the major excretory ducts ## Footnote The acinus, or the terminal salivary gland unit, produces saliva that travels into the intercalated ducts. These ducts coalesce to form the intralobular ducts, which flow into interlobular ducts, lobular ducts, lobar ducts, and finally the major excretory ducts.

Question 45

What are the two types of cells found in most salivary glands?

Answer 45

Histologically, most salivary glands consist of a combination of serous and mucus-producing cell

Question 46

Define acinus in the context of salivary glands

Answer 46

The acinus is the terminal salivary gland unit that produces saliva

Question 47

# Parotid? Mandibular? Sublingual? Zygomatic? Which glands produce more serous secretions?

Answer 47

Parotid and Mandibular ## Footnote Evaluation of the location and viscosity of the aspirated fluid may therefore provide clues in identifying the offending gland.

Question 48

Which glands produce mucus secretions? | Higher propotion of mucus

Answer 48

Sublingual and Zygomatic ## Footnote Evaluation of the location and viscosity of the aspirated fluid may therefore provide clues in identifying the offending gland.

Question 49

Saliva undergoes two phases before excretion into the oral cavity. What happens in phase 1?

Answer 49

Phase one: begins with **production** of saliva within the acinus. The acinar cells absorb Na+ , which helps to draw water in, creating **sodium-rich saliva**. After the saliva flows into the collecting ducts

Question 50

Saliva undergoes two phases before excretion into the oral cavity. What happens in phase 2?

Answer 50

Phase two begins, with **active reabsorption of Na+** and **secretion** of **HCO3 − and K+**. This process occurs mainly in the** intralobular duct epithelium**, which is formed by **tall columnar epithelial cells**

Question 51

Saliva excreted into the oral cavity is rich in ............

Answer 51

**HCO3 − and K+ **

Question 52

Which nervous system provides the majority of nervous control of the salivary glands?

Answer 52

Autonomic nervous system ## Footnote Split into the parasympathetic and sympathetic

Question 53

Stimulation of the parasympathetic nervous system **increases production** of saliva by which two methods?

Answer 53

1. Vasodilation of the blood supply 2. Stimulation of **cyclic guanosine monophosphate** (cGMP) | cGMP directly upregulates the activity of the acinar cell

Question 54

Parasympathetic supply travels mainly via which nerves? ## Footnote For salivary excretion

Answer 54

1. Facial 2. Mandibular

Question 55

True or false: Sympathetic stimulation of the salivary gland causes major inhibition in sallivary flow.

Answer 55

False: Sympathetic stimulation of the salivary glands causes **minor** inhibition in salivary flow, after an initial **increase** from **contraction** of the **myoepithelial cells**

Question 56

Sialadenosis cause is typically.... | noninflammatory, nonneoplastic, bilateral swelling of the salivary gland ## Footnote Non surgical salivary gland disease

Answer 56

Unknown | The cause is unknown

Question 57

Sialadenosis more commonly affects which gland?

Answer 57

Mandibular salivary gland

Question 58

Clinical signs: retching, gulping, lip smacking, hypersalivation and weight loss...whats the possible diagnosis? | In canines

Answer 58

Sialadenosis

Question 59

True of fasle: Sialadenosis affected glands are enlarged and typically painful

Answer 59

False. Affected glands are enlarged and typically nonpainful

Question 60

Describe histological changes to sialadenosis affected glands

Answer 60

Affected glands show minimal to no changes.

Question 61

Abnormalities of the ..... are occasionally identified in conjuction with sialadenosis | Part of the gastrointestinal tract

Answer 61

Eosophagus

Question 62

How do you diagnose sialadenosis?

Answer 62

Usually based on exclusion of other causes

Question 63

What treatment has been sucessful for sialadenosis, and why?

Answer 63

* Phenobarbital (1-2 mg/kg PO q12h) * May improve clinical signs within 1 to 2 days * *Response *to phenobarbital and detection of abnormalities on *electroencephalography* may support a diagnosis of** limbic epilepsy** | Lifelong phenobarbital therapy may be required. ## Footnote Clinical signs are not alleviated by glucocorticoids, antibiotics, or surgical removal of the affected gland(s).

Question 64

Salivary glands can develop inflammation that occasionally progresses to glandular necrosis and ductal metaplasia - what is this called?

Answer 64

Noninfectious Sialadenitis and Necrotizing Sialometaplasia

Question 65

What clinical signs differentiate Noninfectious Sialadenitis/Necrotizing Sialometaplasia FROM Sialadenosis | Name 2

Answer 65

1. Pain on palpation of glands 2. Vomiting

Question 66

Name a typical breed predisposed to: Noninfectious Sialadenitis and Necrotizing Sialometaplasia

Answer 66

Terrier breeds

Question 67

True of false: Cytology is appropriate is diagnosis of noninfectious sialadenitis and necrotizing sialometaplasia

Answer 67

False: cytologic changes can be confused with inflamed, neoplastic glands, the diagnosis is based on **histologic** findings

Question 68

Name the diagnosis: histologic findings of lobular necrosis, inflammation, squamous metaplasia, infarction, and hypertrophy of ductal epithelium

Answer 68

Sialadenitis and necrotizing sialometaplasia ## Footnote Noninfectious Sialadenitis

Question 69

What is the theorised link between esophageal or gastrointestinal disease concurrently with necrotizing salivary gland disease?

Answer 69

*Hyperstimulation* of the **vagus nerve**, resulting in a neural reflex syndrome similar to that seen with hypertrophic osteopathy, except that the salivary glands are the efferent target organ instead of the periosteum. ## Footnote Resulting in a neural reflex syndrome similar to that seen with hypertrophic osteopathy, except that the salivary glands are the efferent target organ instead of the periosteum

Question 70

True or false: Treament for sialadenitis and necrotizing sialometaplasia should be focused on addressing any oesophageal disease present as well as a trial of phenobarbital

Answer 70

True: Response to phenobarbital has been reported, which supports limbic epilepsy as a potential cause. Surgical removal of the affected salivary gland(s) and medical management with steroids and antibiotics alone do not appear to consistently resolve the clinical signs ## Footnote Therefore treatment should be focused on addressing any esophageal disease present, as well as a trial of phenobarbital.

Question 71

Define sialocele

Answer 71

Collections of saliva within subcutaneous tissue

Question 72

True or false: Sialocele is a type of cyst

Answer 72

False: saliva-filled cavities are lined by inflammatory connective tissue and are not true cysts

Question 73

What is the most common source of saliva leakage in sialocele formation?

Answer 73

**Sublingual** salivary gland or duct

Question 74

Name 4 causes of sialoceles

Answer 74

1. trauma (nonsurgical and surgical) 2. sialoliths 3. foreign bodies 4. neoplasia 5. majority have an **unknown** cause

Question 75

Name the sialocele location based on **exophthalmos**

Answer 75

Zygomatic sialocele

Question 76

Name 4 breeds predisposed to sialoceles

Answer 76

1. Poodles 2. German shepherds 3. Australian silky terriers 4. Dachshunds | No sex predisposition has been consistently identified

Question 77

Name the sialocele location based on laboured breathing

Answer 77

Pharyngeal sialocele

Question 78

Name the sialocele location based on dysphagia

Answer 78

Sublingual sialocele or ranula

Question 79

Name the sialocele location based on intermandibular or cranioventral cervical swelling

Answer 79

Cervical sialocele

Question 80

Name the diagnosis: Fluid-filled mass, contains a viscous, honey-colored, clear or blood-tinged fluid

Answer 80

Sialocele

Question 81

Whats the diagnosis?

Answer 81

Sialocele * small-moderate numbers of nondegenerate nucleated cells * diffuse/irregular clumps of homogenous pink/violet staining mucin * macrophages may contain abundant, foamy cytoplasm * mucin-specific stain: **periodic acid–Schiff**

Question 82

Name the mucin-specific stain

Answer 82

**periodic acid–Schiff**

Question 83

Where is sialocele? What is the choice of treament? | Exophthalmos, protrusion of the third eyelid, painless orbital swelling

Answer 83

**Zygomatic.** * Sialadenectomy. * Use of a sclerosing agent has also been proposed.

Question 84

Where is sialocele? What is the choice of treament? ## Footnote Swelling caudal dorsal or lateral pharynx, just rostral to the level of the epiglottis. Labored breathing or stridor

Answer 84

**Pharyngeal. ** * Acute obstruction - immediate drainage (via incision) or temporary tracheostomy. * After stabilisation redundant tissue resected and sialocele marsupialized. The origin of the sialocele (sublingual and mandibular salivary gland and duct complex), should also be removed.

Question 85

Name the predominant breed and sex for pharyngeal sialoceles

Answer 85

**Miniature poodles** and **male** dogs

Question 86

Paper reported concurrent ipsilateral cervical sialoceles with pharyngeal sialoceles in what percentage of affected dogs? 1. 23% 2. 33% 3. 43% 4. 54%

Answer 86

3. 43% ## Footnote Benjamino KP, Birchard SJ, Niles JD, et al: Pharyngeal Mucoceles in Dogs: 14 cases. J Am Anim Hosp Assoc 48: 31–35, 2012.

Question 87

Name the sialocele

Answer 87

Sublingual: AKA ranula

Question 88

How do you treat a sublingual sialocele?

Answer 88

* Removal of the **ipsilateral mandibular and sublingual salivary gland and duct complex** (especially rostral glandular tissue). * Along with sialadenectomy, the ranula should be **drained and marsupialized** into the oral cavity.

Question 89

Where does a ranula leak from?

Answer 89

Leakage of the **rostral sublingual salivary glands or duct**

Question 90

Name the sialocele ## Footnote Swelling in the intermandibular or cranioventral cervical region

Answer 90

Cervical

Question 91

True of False: Conservative treatment of sialoceles is not recomended due to high rate of recurrence

Answer 91

True: Conservative treatment is **not** recommended for definitive treatment because of the high rate of recurrence

Question 92

What is the prognosis following sialedectomy?

Answer 92

**Excellent** when the affected salivary gland and duct are removed entirely.

Question 93

Name 5 postoperative complications following sialedanectomy

Answer 93

1. Seroma 2. Infection 3. Recurrence 4. Sublingual swelling 5. Bleeding

Question 94

True or False: Placement of drains into the sialocele **does** decrease the risk for seroma formation

Answer 94

False: Placement of drains into the sialocele **does not** decrease the risk for seroma formation

Question 95

What is the recurrence rate following sialedenectomy and why?

Answer 95

**5% or less** and usually results from incomplete removal of the affected gland(s) or removal of the wrong gland

Question 96

Name how using the following methods you can identify a gland causing a sialocele: 1. Physical 2. Imaging 3. Surgery

Answer 96

* **Physical:** Chronic intermandibular cervical sialoceles - place in dorsal recumbency under GA, the fluid accumulation usually displaces laterally to the affected side * **Imaging:** Sialography, CT, MRI * **Exploratory surgery:** affected glands are usually adherent to the inner or outer wall of the mucocele capsule. If any question remains, bilateral sialadenectomy can be performed.

Question 97

True of false: Dry mouth is an expected consequence following sialadenctomy

Answer 97

False: Because of the redundancy in saliva production from multiple glands, **dry mouth is not expected** after bilateral procedures

Question 98

Where are sialoliths commonly associated?

Answer 98

Rarely reported. Most often associated with the **parotid duct** but have also been reported in the mandibular sublingual duct complex

Question 99

Name 4 sialolith compositions: ## Footnote 7 available

Answer 99

* calcium * oxalate * phosphate * magnesium * carbonate * ammonium * nonmineral proteinaceous material ## Footnote Stone-like structures identified within a sialocele composed of a proteinaceous material are not true sialoliths; rather, they are thought to be mineralized folds of sialocele lining that have sloughed into the sialocele.

Question 100

Whats the diagnosis? Swelling on the lateral aspect of the face that may be painful and may regress and then reoccur.

Answer 100

Parotid sialolith

Question 101

Diagnosis of a sialolith can be based on 3 things, name them.

Answer 101

* Palpation * Radiographs * CT

Question 102

Treatment depends on location of the sialolith, presence of infection or stone, ease of duct and gland removal, suspicion of future duct stricture or fibrosis, and likelihood of stone recurrence. Name 4 different surgical technique options.

Answer 102

1. **Duct-gland complex** can be **surgically removed** 2. Located close to the oral papilla of the duct, an **incision** can be made through the **mucosa** directly over the stone which is removed - The incision is left to **heal by second intention** 3. **Complete ligation** of the duct, **resection and anastomosis**, and **primary repair** of the affected duct 4. **Duct dilatation** is the primary clinical sign - **marsupialization** of the duct into the oral cavity has been reported as a successful option

Question 103

Salivary gland neoplasia is uncommmon in dogs and cats. What is the incidence in a percentage?

Answer 103

0.17%

Question 104

Histological origin of salivary gland neoplasia?

Answer 104

Epithelial

Question 105

Name 2 salivary gland neoplasias

Answer 105

1. Adenocarcinoma 2. Acinic carcinoma | These are the majority. ## Footnote Several other benign and malignant variants have also been reported.

Question 106

Which glands are the most commonly affected by neoplasia? | 2 glands

Answer 106

**Mandibular** and** parotid** salivary glands ## Footnote Tumor invasion into local tissues and spread to regional lymph nodes occasionally occur.

Question 107

In a study, what percentage of felines and canines had salivary gland neoplasia with regional lymph node involvement: 1. 39% of cats and 17% of dogs 2. 17% of cats and 39% of dogs 3. 29% of cats and 17% of dogs 4. 39% of cats and 27% of dogs In addition, what is the rate for distant metastasis?

Answer 107

1. 39% of cats and 17% of dogs Distant metastasis at presentation less common (16% for cats and 8% for dogs).

Question 108

Therapy for salivary gland neoplasia is initially directed toward aggressive cytoreduction of gross disease. Postoperative adjuvant therapy may be recommended based on what?

Answer 108

Histologic findings and margin evaluation

Question 109

What is the prognosis for salivary gland cancer?

Answer 109

largely unknown

Question 110

What is the median survival time for salivary gland neoplasia?

Answer 110

**74 to 550 days** The prognosis is not correlated with histologic grade but is associated with **stage of disease**

Question 111

Name two different approaches for sublingual and mandibular sialadenectomy ## Footnote Although most cervical sialoceles originate from the sublingual gland-duct complex, the mandibular gland and duct are removed as well because of their intimate anatomic association with the sublingual glands and duct

Answer 111

1. Lateral approach - combined with duct traction or tunneling under the digastricus muscle 2. Ventral approach ## Footnote In one cadaveric study using the lateral approach combined with tunneling under the digastricus muscle, complete removal of the rostral salivary tissue was noted in 13 of 15 cadaveric salivary chains. Leaving remnants of the rostral salivary glands could result in sialocele recurrence.

Question 112

Name the preferred approach for sublingual and mandibular sialadenectomy and why? | As per Tobias authors

Answer 112

Ventral approach is preferred by the authors because it permits removal of the entire sublingual gland-duct complex

Question 113

Describe the ventral approach for sublingual and mandibular sialadenectomy

Answer 113

* Incision: starting 4 to 5 cm caudal to the mandibular ramus on the affected side and extending rostrally toward the mandibular symphysis * Platysma muscle incised: allows ID of the external jugular bifurcation; the mandibular gland sits at or just cranial to this bifurcation * Tissues are bluntly dissected to expose the capsule covering the mandibular and sublingual salivary glands * Glands must be differentiated from mandibular lymph nodes (which are more rostral and ventral at this location) * Capsule is incised and bluntly dissected off the glandular tissue to allow ligation of vessels on the medial side of the gland * Gland complex is retracted caudally - blunt dissection of the sublingual gland under (dorsal to) the digastricus muscle * Place hemostat from rostral to caudal under the digastricus muscle, the ducts are clamped just rostral to the large glandular complex - mandibular and main sublingual gland are excised * The remaining ducts and sublingual glands are pulled under the digastricus muscle * Blunt and sharp dissection are continued rostrally to the level of the **lingual nerve**; the **mylohyoideus muscle** is incised for best exposure of the rostral glandular tissue and lingual nerve * Glandular tissue removed up to the lingual nerve - exect if ranular present * The mylohyoideus, platysma muscle, and subcutaneous tissues are reapposed with an absorbable monofilament suture ## Footnote If bilateral gland removal is to be performed, a midline incision can be made.

Question 114

If a ranula is present, discribe how surgery may differ

Answer 114

Dissection should **continue rostral to the lingual nerve** under the mylohyoideus to remove all of the glandular tissue up to the **sublingual caruncle **. The duct is ligated as rostrally as possible and transected.

Question 115

Should a sialocele be dissected out?

Answer 115

The sialocele can be dissected out and removed; however, incisional drainage with or without drain placement is much less traumatic and time consuming and has similar results.

Question 116

Describe the lateral approach for sublingual and mandibular sialadenectomy

Answer 116

* Lateral recumbency with the affected side upwards and the neck extended * Jugular bifurcation is identified, and a horizontally oriented incision is made over the expected location of the mandibular salivary gland, between the **linguofacial** and **maxillary veins** * Overlying subcutaneous tissues are removed with blunt and sharp dissection to expose the capsule of the sialocele (or mandibular gland) - capsule is perforated, and the contents are removed with suction * Next the mandibular and largest sublingual glands are identified and dissected free from surrounding tissues * Ligation of the blood supply (entering the rostromedial surfaces of the glands) may be necessary during dissection * Blunt dissection continues rostrally along, and parallel with, the ducts, exposing more clusters of sublingual salivary tissue * A hemostat is placed distally across the ducts, and traction is applied to the gland-duct complex * Blunt dissection of fascia proceeds between the duct-gland complex and surrounding muscles (**digastricus caudomedially and masseter muscle rostrolaterally**); the** lingual branch **of the trigeminal nerve may need to be dissected free of the duct at this time * Hemostat can be replaced more distally as more duct and glandular tissue are exposed * Ducts can either be ligated distally and transected just proximal to the ligature, or they can be separated from oral cavity tissue with slow, steady traction * Alternatively, the duct salivary gland can be transected proximal to the hemostat, and a Carmalt hemostatic forceps passed medial to the rostral digastricus muscle from a caudoventral to rostrodorsal direction * Transected ends of the remaining salivary ducts are grasped with the tips of the forceps and pulled medial to the rostral digastricus muscle to allow further dissection of the duct

Question 117

Describe a Zygomatic sialadenectomy

Answer 117

* Incision is made horizontally through the skin and subcutaneous tissue over the dorsal aspect of the arch * Aponeurosis of the masseter muscle is reflected off of the ventral aspect of the zygomatic arch, and the orbital fascia is reflected dorsally * Portion of the rostrolateral zygomatic arch is removed, as necessary, with a bone saw or rongeurs to gain access to the region of the zygomatic gland * Orbital fat is dissected and retracted to gain access to glandular tissue * Gland resides medial to the zygomatic arch and adjacent to the globe on the rostroventrolateral aspect * Gland is gently retracted and dissected free from surrounding tissue * A branch of the **infraorbital (malar) artery** supplying the salivary gland is accessed for ligation by dorsal retraction of the gland * During closure, orbital fascia is reapposed to the aponeurosis of the masseter muscle, and subcutis and skin are closed routinely ## Footnote Careful dissection is required due to sensitive structures in that area and anatomic changes caused by the presence of the sialocele.

Question 118

Describe a Parotid sialadenectomy

Answer 118

* Patient in lateral recumbency. The skin is incised over the vertical ear canal, starting at a point below the external acoustic meatus and extending ventrally to the level of the caudal angle of the mandible * Platysma and parotidoauricularis muscles are incised to gain exposure to the glandular tissue * Ligation and division of the **caudal auricular vein** * Parotid gland is bluntly dissected from its attachments, beginning at its dorsocaudal border - continued rostrally, separating the gland from the ear canal and other surrounding tissues * *Dissection should proceed cautiously near the horizontal canal in an attempt to spare the facial nerve* * Several small vessels that require cauterization or ligation will be encountered during the dissection of the medial side of the gland * The gland is dissected out to the level of the duct, which is freed from surrounding tissues, ligated, and divided * *If clinical presentation included lateral cheek swelling, the accessory parotid gland just dorsal to the parotid duct should also be dissected free and removed* ## Footnote Complete removal of the parotid salivary gland is difficult - dissection extends to the region of the horizontal ear canal, facial nerve paresis or paralysis is a common complication.

Question 119

Sublingual sialoceles (ranulas) are treated by **marsupialization** of the fluid-filled pocket and removal of the mandibular and sublingual salivary gland complex, including as much of the rostral submandibular glandular tissue as possible. Descibe options for ranula marsupialization.

Answer 119

1. Large full-thickness oval area of the tissue overlying the sublingual sialoceles is excised. The remaining external (oral) mucosa is sutured to the lining of the sialoceles with small-gauge, absorbable, monofilament suture 2. The mucosal edge is folded inward and sutured in place, similar to hemming a pair of pants. ## Footnote Because there is not a true epithelial lining of the sialocele, the mucosa will try to heal in the face of marsupialization. Therefore prevention of recurrence can be ensured only by removal of the glandular source of saliva.