Salivary gland disorders overview

Question 1

During what week of embryogenesis does the parotid gland develop?

Answer 1

The 7th embryonic week

Question 2

Where does the parotid gland originate during
development, and what is its relationship to the
facial nerve?

Answer 2

The parotid gland originates at the site of the eventual duct
orifice and grows in a posterior direction. The facial nerve
develops in an anterior direction. The facial nerve eventually becomes surrounded by parotid gland tissue.

Question 3

What are the different types of acini in the salivary glands?

Answer 3

There are three types: serous acini are found in the parotid, mucous acini in the sublingual and minor salivary glands, and mixed acini, which are found in the submandibular
gland.

Question 4

Describe the salivary gland duct system.

Answer 4

An acinus is the main secretory component that is composed of a central lumen surrounded by acinar cells that produce saliva. Intercalated ducts form early connections between acini. Both acini and intercalated ducts are lined with myoepithelial cells that help to contract and
propel saliva forward. Intercalated ducts feed into larger striated ducts and then into excretory ducts.

Question 5

What is the relationship of lymph nodes to the

salivary glands?

Answer 5

Lymph nodes develop within the pseudocapsule of the

parotid gland, leading to intraparotid lymph nodes. No other salivary gland has intraglandular lymph nodes.

Question 6

Where are intraparotid lymph nodes typically

located?

Answer 6

The parotid gland is the only salivary gland with lymph
nodes actually within the gland. Most intraparotid lymph
nodes lie within the superficial lobe, although they are
present in both the superficial and deep lobes.

Question 7

Describe the path of the Stenson duct (parotid duct).

Answer 7

It originates from superficial portion of parotid gland,
travels anteriorly on the masseter muscle and buccinator fat
pad, and then travels medially to pierce the buccinator muscle. The duct empties lateral to the second maxillary molar.

Question 8

Where does the Wharton duct (submandibular

duct) empty into the oral cavity?

Answer 8

The submandibular duct empties just lateral to the lingual

frenulum.

Question 9

What fascial layer forms the parotid fascia?

Answer 9

The parotid fascia is continuous with the superficial layer of the deep cervical fascia.

Question 10

Describe the fascial connections of the superficial musculosaponeurotic system (SMAS) and its relationship to the parotid gland.

Answer 10

The SMAS gives support to the many muscles of facial
expression. Over the parotid gland, it is located just
superficial to the parotid fascia.

Question 11

What is the autonomic nerve supply of the parotid glands?

Answer 11

The parasympathetic nervous system supplies the parotid
gland via the glossopharyngeal nerve (cranial nerve IX). The sympathetic nervous system supplies the gland via the superior cervical ganglion.

Question 12

Describe the path of the parasympathetic innervation of the parotid gland.

Answer 12

Parasympathetics that are part of the glossopharyngeal
nerve (tympanic branch) enter the middle ear through the tympanic canaliculus as the Jacobson nerve. They then exit the middle ear cavity and travel through the middle cranial fossa as the lesser petrosal nerve. The lesser petrosal nerve exits the skull base through the foramen ovale and travels to the otic ganglion. After synapsing in the otic ganglion, postsynaptic fibers are carried via the auriculotemporal
nerve to the parotid gland.

Question 13

Define accessory parotid gland tissue.

Answer 13

Accessory parotid tissue lies anterior to the main parotid gland between the skin and the masseter muscle.

Question 14

What are important anatomical landmarks for identification of the facial nerve during parotidectomy?

Answer 14

The facial nerve can be located via its relationships to the
tragal pointer, tympanomastoid suture line, and the
attachment of posterior digastric muscle to digastric
groove, or it can be identified distally and dissected in a retrograde fashion or drilled out from the mastoid bone and
traced anterograde.

Question 15

How does the parotid gland change histologically

with age?

Answer 15

There is an increase in adipose cells in the parotid parenchyma with age.

Question 16

In which anatomical triangle is the submandibular

gland located, and what are its boundaries?

Answer 16

The submandibular triangle: its boundaries are the anterior and posterior bellies of the digastric muscle and the inferior aspect of the mandible.

Question 17

What nerve carries the parasympathetic supply to the submandibular gland?

Answer 17

The chorda tympani carries parasympathetic fibers to the submandibular and sublingual glands via the lingual nerve.

Question 18

Secretomotor function of the submandibular and sublingual glands is controlled by which nerve?

Answer 18

Parasympathetic contribution of facial nerve (nervus intermedius) via the chorda tympani

Question 19

Where is the lingual nerve found during a

submandibular gland excision?

Answer 19

The lingual nerve is found deep to the submandibular
gland. With inferior retraction of the gland and anterior retraction of the mylohyoid muscle, the lingual nerve and
the submandibular ganglion can be exposed.

Question 20

What is the relationship of the lingual nerve to the submandibular duct in the floor of mouth?

Answer 20

The lingual nerve courses from a posterolateral to

anteromedial position, passing below the Wharton duct.

Question 21

Where are the facial artery and vein found in

relation to the submandibular gland?

Answer 21

The facial vein is found on the lateral surface of the
submandibular gland; the facial artery is located on the
posterior surface of the gland and is often ligated on both
the superior and inferior aspect of the gland during
submandibular gland excision.

Question 22

Name the ducts through which the sublingual

gland drains.

Answer 22

The sublingual gland drains into the mouth via the smaller duct of Rivinus (which empties into the floor of the mouth or into submandibular duct) and larger duct of Bartholin (empties into submandibular duct).

Question 23

What structures border the sublingual gland?

Answer 23

The sublingual gland is bordered by the mandible, genioglossus muscle, and mylohyoid muscle.

Question 24

What structures are important to be aware of during excision of the sublingual gland?

Answer 24

The lingual nerve and Wharton (submandibular) duct run between the sublingual gland and the genioglossus muscle.

Question 25

Where are most minor salivary glands located?

Answer 25

The hard palate mucosa harbors most of the mouth’s minor salivary glands.

Question 26

What are the functions of saliva?

Answer 26

There are many functions of saliva, the most important being lubrication of food, buffering and prevention of caries, mineralization of teeth, antibacterial and bactericidal function, digestion, and taste.

Question 27

List the order of salivary gland saliva production

from most serous to most viscous.

Answer 27

In order from most serous to most viscous: parotid
gland > submandibular gland > sublingual gland > minor
salivary glands

Question 28

What are the important physical examination
findings to assess when evaluating a salivary gland
mass?

Answer 28

One should appreciate the size of the mass, invasion of overlying skin, mobility versus fixation, tenderness to palpation, facial nerve function, trismus, pharyngeal fullness, and whether there is evidence of a primary skin or scalp lesion.

Question 29

Typically, how large must a parapharyngeal mass be to visualize it intraorally?

Answer 29

Usually, a parapharyngeal mass must be at least 3.5 cm to visualize it intraorally.

Question 30

Name the key surgical landmarks associated with the location of the facial nerve during parotidectomy?

Answer 30

● The facial nerve lies 1 to 1.5 cm deep and inferior to the
tragal pointer.
● The attachment of the posterior belly of the digastric
muscle to the digastric ridge identifies the plane of nerve.
● The nerve lies 6 to 8 mm deep to the tympanomastoid
suture.

Question 31

What is the pathophysiology of Frey syndrome after parotidectomy?

Answer 31

Postganglionic parasympathetic secretomotor fibers carried on the auriculotemporal nerve, which normally innervate the parotid gland tissue, aberrantly reinnervate sweat glands of the overlying skin.

Question 32

Name an objective test for Frey syndrome.

Answer 32

The Minor starch-iodine test is an objective measure of
gustatory sweating. The preauricular region is coated with
iodine, allowed to dry, and then dusted with starch. The patient is then given a sialagogue, and a positive test
(indicating Frey syndrome) results in dark blue spots where
sweat has dissolved the starch and reacted with iodine.

Question 33

What are the treatment options for Frey syndrome?

Answer 33

Treatment options are broad and depend on the patient’s discomfort level. Options range from observation and use
of antiperspirant, to medications such as glycopyrrolate, or
more invasive therapy such as botulinum toxin injection or
tympanic neurectomy.

Question 34

What techniques can be used to reduce post-parotidectomy gustatory sweating?

Answer 34

The most important surgical techniques to prevent Frey syndrome are raising a thick skin flap and doing only a
partial superficial parotidectomy.

Question 35

What additional techniques are being used to try

to reduce post parotidectomy gustatory sweating?

Answer 35

Rotational sternocleidomastoid flaps, fat transfer, Alloderm implants, and superficial musculoaponeurotic system interposition are all being used.