Ch 87 Oral cavity

Question 1

Label 1-10 on the attached diagram

Answer 1

1 - Vestibule

2 - Canine

3 - Hard Palate

4 - Soft Palate

5- Tongue

6 - Sublingual Caruncle

7 - Palaoglossal arch

8 - Palatine Tonsil

9 - Frenulum

10 - Philtrum

Question 2

Define oropharynx, oral cavity proper and oral vestibule

Answer 2

Oropharynx - Space ventral to the soft palate bound caudally by the pharyngeal wall

Oral cavity proper - Space between the lower and upper dental arcades

Oral vestibule - Real and potential space lateral to the teeth and inside the cheeks

Question 3

Label the arteries and their associated branches which supply the lips and cheeks

Answer 3

facial artery supplying the lower lip and cheek infraorbital artery supplying the upper lip and cheek

Question 4

What nerve supply motor function and sensation to the cheeks?

Answer 4

Motor function - Facial Nerve (CNVII)

Sensation - Trigeminal Nerve (CNV)

Question 5

where do the salivavy gland ducts exit?

Answer 5

• mandibular and sublingual ducts course under the mucosal folds and open at the caruncle
• oral vestibule > Parotid and zymogatic

Question 6

tongue

Answer 6

• root of the tongue consists of a set of three paired extrinsic muscles: the styloglossus, hyoglossus, and genioglossus
• under control of the hypoglossal nerves.
• tongue is covered with a thick mucous membrane consisting of cornified squamous epithelium
• Branches of the trigeminal, facial, and glossopharyngeal nerves play a role in taste, pain, heat, and sensation
• the right and left lingual arteries (branch of external carotid a.) anastomose throughout parenchyma of the tongue muscle

Question 7

List the three extrinsic muscles of the tongue and its associated function

Answer 7

Styloglossus - Draws the tongue caudally

Hyoglossus - Retracts and depresses the tongue

Genioglossus - Depress and protrude the tongue

All innervated by the hypoglossal nerve

Question 8

List the fibre units which make up the intrinsic muscles of the tongue

Answer 8

Superficial longitudinal

Deep longitudinal

Transverse

Perpendicular

All innervated by the hypoglossal nerve

Question 9

What is the lyssa?

Answer 9

A tube-like structure of muscle, fat and somtimes cartilage encased in a dense sheath of connective tissue that lies on the median plane on the ventral tongue.

Its function is unclear but one theory is that is acts as a stretch receptor for the tongue

Question 10

List the paired muscles of the soft palate

Answer 10

Palatine

Tensor and Levator Veli Palatini

Pterygopharyngeal

Palatopharyngeal (Make up the palatopharyngeal arches)

Question 11

What nerve supply the muscle of the soft palate?

Answer 11

CN IX and X

(vagus and glossopharyngeal)

Question 12

List all the tonsils which dogs and cats possess

Answer 12

Paired palatine tonsils

Lingual tonsil (base of tongue, not grossly appreciable)

Pharyngeal tonsil (on roof of nasopharynx)

Cats also have paired paraepiglottic tonsils (craniolateral to base of epiglottis, macroscopocally visible in some)

Question 13

List the three stages (and associated sub stages) of deglutition

Answer 13

(1) Oropharyngeal (oral, pharyngeal, pharyngoesophageal)
(2) Oesophageal
(3) Gastroesophageal

Question 14

Describe the three subphases of the oropharyngeal phase of deglutition

Answer 14

• Oral - Formation of a food bolus by compression of food between tongue and palate and then propelling towards pharynx. This is the only stage that is completely voluntary (CN V, VII, XII)
• Pharyngeal stage - Tongue and pharyngeal constrictor muscles transport food, epiglottis covers the glottis and soft palate presses against nasopharyngeal wall (Swallowing center, CN IX, X)
• Pharyngoesophageal - Passage of food through cricopharyngeal sphincter and into the oesophagus (CN IX, X)

Question 15

Which LNs drain the oral cavity?

Answer 15

Parotid
Mandibular
Medial retropharyngeal
These all subsequently drain into the superficial cervical

Question 16

Lymph vessels of the head and neck can cross midline, so nodes on both sides of the head and neck should be evaluated, even when the lesion is unilateral
palpation is an insensitive and nonspecific method of evaluating for metastasis and enlargement is nonspecific for metastasis. Computed tomography (CT) is more sensitive in the detection of retropharyngeal lymph node enlargement

Question 17

What solutions can be used for surgical prep of the oral mucosa?

Answer 17

Povidone Iodine
0.2% chlorhexidine gluconate

Question 18

Why cant spring-loaded gags be used in cats?

Answer 18

Causes compression of the maxillary arteries resulting in neuro deficits, including blindness

Question 19

Disorders of the Lips and Cheeks

Question 20

What is tight lip syndrome and in what breed is it seen?

What are the treatment options?

Answer 20

The rostral edge of the lip tissue is pulled over the mandibular dental arcade resulting in trauma to the lip tissue during mastication and in some cases inhibiting normal mandibular growth and tooth eruption.

This condition has only seen seen in Shar-Peis.

Treatment options: Incising lip mucosa at gingival margin, excising a segment of skin on chin to pull lip ventrally, or deepening the rostral and lateral vestibule

Question 21

congenital

Answer 21

• Primary cleft palate
• tight lip syndrome
• Congenital redundancy and eversion of the lower lip

Question 22

What is the procedure in the picture called? What condition is it used to treat?

Answer 22

Antidrool Chelioplasty

Used to treat congenital redundancy and eversion of the lower lip.

Alternative treatment - Redundant fold resected with full-thickeness wedge resection

Question 23

trauma - avulsion

Answer 23

• Small avulsions will heal quickly by second intention, provided adequate tissue lavage and debridement have been performed.
• Gingival tissue has a comparatively lower suture pull-out strength > suture around intact incisor teeth or small holes are drilled through the mandible

Question 24

What are the most common forms of neoplasia of the lips and cheeks in dogs and cats?

Answer 24

Dogs - Melanomas and SCC

Cats - (Rare) SCC, MCT and FSA

Question 25

metastatic rates for oral malignant melanoma? non-tonsil SCC? cats oral SCC?

Answer 25

- oral malignant melanomas - 12.9% to 59% - oral nontonsillar SCC 0% to 37.5% - oral SCC in cats 31%

Question 26

Excisional techniques

Answer 26

- proper tissue-handling techniques - Full-thickness labial advancement flap -

Question 27

What is the MST of dogs with well differentiated melanomas treated with surgical excision?

Answer 27

34 months

Question 28

tongue

Question 29

What is ankyloglossia? What breed is it reported in? What is the treatment

Answer 29

Ankyloglossia is a condition where the frenulum is abnormally short and thickened, restricting movement of the tongue. It is seen in Anatolian Shepherd Dogs Treatment in frenuloplasty - surgical resection of the tissue band

Question 30

What is Feline Oral Pain Syndrome (FOPS)? What breed is it reported in? What is the treatment?

Answer 30

FOPS is a syndrome of exaggerated licking and chewing movements with pawing at the mouth. Oral self-mutilation, often lateralised to one side of the mouth, can result. Most common in Burmese cats Most cats respond to antiepileptic drugs | suspect condition of neuropathic (trigeminal?) pain and allodynia

Question 31

trauma

Answer 31

- Burns and chemical injuries may not reach full necrotic potential for several weeks, so definitive repair of these lesions may need to be delayed. - Most clean lacerations can be closed primarily using aseptic technique and gentle tissue handling.

Question 32

What are the most common lingual tumours in dogs and cats?

Answer 32

**Dogs - Malignant melanoma and SCC** (Mast cell tumor, hemangiosarcoma, granular cell tumor, chondrosarcoma, squamous papilloma, plasmacytoma, fibrosarcoma, and ectopic thyroid carcinoma) **Cats - SCC** > 61%, most commonly on ventral aspect close to frenulum (Fibrosarcoma, fibromatous epulis, and lymphosarcoma, hyperplastic/eosinphilic lesions)

Question 33

dx

Answer 33

- Melanomas are often darkly pigmented; however, up to 33% of all malignant melanomas in the mouth are amelanotic - Staging ideally consists of cross-sectional imaging of the head, neck, and thorax for suspected neoplastic lesions and sampling of regional lymph nodes. - Because only 54% of dogs with regional lymph node metastasis have mandibular lymph node involvement, sampling the medial retropharyngeal and parotid lymph nodes will provide a more accurate staging assessment.

Question 34

What is the recommended surgical margin for neoplastic lingual lesions?

Answer 34

2cm

Question 35

List the different types of glossectomy and define each

Answer 35

Wedge glossectomy - Acceptable for small malignant tumour or benign masses requiring less aggressive excision Partial glossectomy - Amputation of all or part of the apex of the tongue, rostral to the frenulum Subtotal glossectomy - Removal of the entire apex and a portion of the genioglossus, geniohyoid or both, caudal to the frenulum Near total glossectomy - Removal of >75% of the tongue Total glossectomy - Amputation or removal of the entire tongue

Question 36

List some methods of achieveing adequate haemostasis during glossectomy

Answer 36

Using electrosurgery Laser excision Preplacement of mattress sutures outside of surgical margins prior to excision

Question 37

What crystal are deposited with calcinosis circumscripta? What are some causes of this disorder? What percentage of cases are seen in the tongue?

Answer 37

Calcium hydroxyapatite and calcium phosphate crystals Causes: - Dystrophic (Repetitive injury) - Abnormal Ca and phosphate metabolism secondary to renal failure - Idiopathic 23% of cases are seen in the tongue (2nd most common)

Question 38

What are some DDx which can closely resemble lingual neoplasia?

Answer 38

Chronic periodontal disease causing hyperplastic gingiva Eosinophilic granuloma Plasmacytic stomatitis

Question 39

List reported risk factors of development of oral SCC in cats

Answer 39

Diets consisting mainly of canned food Eating canned tuna on a regular basis Flea collars (5x higher risk compared to those who dont wear flea collars) Live with a smoker (not statistically significant)

Question 40

What % of dogs with oral neoplasia with LN mets, have involvement of the mandibular LNs?

Answer 40

Only 54% - Should also sample the medial retropharyngeal and parotid LNs

Question 41

What is the reported rate of development of mets after surgery in dogs with lingual melanoma and SCC?

Answer 41

Melanoma - 11-71 % (MST 241d) SCC - 6-43% (MST 216d)

Question 42

What are the different MSTs reported for lingual melanoma or SCC excised when under 2cm and compared to over 2cm in size? What is the reported rate of recurrence after glossectomy?

Answer 42

MST of masses over 2cm 207d MST of masses under 2cm 818d Recurrence 28% at a median of 127d

Question 43

What is the prognosis for cats with oral SCC?

Answer 43

Poor - MST 44-203 days

Question 44

glossectomy in dogs and cats

Answer 44

- Long-term effects of glossectomy in dogs are surprisingly few and mild in nature. - resection of up to 50% of the tongue in dogs is well tolerated - may need assistance, such as hand feeding, providing a deep water bucket or soaking kibble with water Information on short- and long-term consequences of tongue resection in cats is scarce - greater unwillingness or inability to adapt to a change in oral structure - o-tube

Question 45

List some examples of structural abnormalities which can result in dysphagia

Answer 45

Congenital palate defects Ankyloglossia Macroglossia Microglossia Tight lip syndrome

Question 46

List some examples of causes of functional dysphagis

Answer 46

Idiopathic (most common) (GOLPP) Peripheral neuropathies Myaesthenia Gravis Brainstem lesions and other intracranial abnormalities

Question 47

What are the three broad categories of causes of dysphagia?

Answer 47

Space-occupying mass Structural congenital abnormalities Functional abnormalities

Question 48

What are the most common pharyngoesophageal dysphagias in the dog?

Answer 48

Cricopharyngeal asynchrony Cricopharyngeal achalasia

Question 49

Penetrating Injuries to the Pharynx

Answer 49

- CS: dysphagia, drooling, depression, oral pain, pain on flexion of the neck, subcutaneous emphysema, blood in the saliva, and pain on opening of the mouth - Plain radiographs for initial diagnostic workup + EUS - Extraluminal gas between fascial planes in the cervical region > can dissect along fascial planes, causing pneumomediastinum or pneumothorax, and make localization difficult - chronic cases: CT or MRI very useful Sx - rigid endoscopy - acute: transoral pharyngeal examination, debridement, and lavage - ventral midline approach (avoid recurrent laryngeal nerves) - C&S - drainage

Question 50

Common sites of pharyngeal penetration

Answer 50

- esophagus, - lateral and dorsal pharyngeal walls - sublingual region

Question 51

Tonsils

Question 52

What is primary tonsillitis?

Answer 52

Inflammation of the tonsils in dogs <1yo causing persistent cough, gagging, dysphagia, depression, pyrexia and anorexia. Tonsils may be bright red, friable and may or may not be enlarged. Treatment consists of antibiotics and analgesics. If recurrent, can consider tonsillectomy

Question 53

List some cause of tonsillar eversion or enlargement

Answer 53

Primary tonsillitis Chronic BOAS Cleft palate Periodontal disease Neoplasia

Question 54

What is the MST of tonsillar SCC with surgical excision in dogs and cats? | feline tonsillar neoplasia is rare

Answer 54

Dogs - 2 months. High rate of early metastasis (73%) and high recurrence rate/incomplete excision Cats - 2-14 weeks Tonsillectomy followed by radiation therapy in dogs resulted in MST of 110d Chemotherapy +/- tonsillectomy or chemotherapy with radiation therapy +/- tonsillectomy had a MST of 212 and 355d respectively

Question 55

Tonsillectomy

Answer 55

- indicated for diagnosis and treatment of neoplasia, tonsillitis or brachycephalic syndrome - transection and hemostasis can be achieved simultaneously with an electrosurgical unit set on a low level or with a laser or vessel sealing device. - complications are rare and include hemorrhage, pharyngeal swelling secondary to tissue trauma, and postoperative aspiration of blood or fluid.

Question 56

Preoperative computed tomography, surgical treatment and long-term outcomes of dogs with abscesses on migrating vegetal foreign bodies and oropharyngeal stick injuries: 39 cases (2010-2021) Manzoni 2023

Answer 56

retrospective study **foreign body was identified on CT in 11 of 39 (30%) cases** and later confirmed at surgery in 10 cases. 28 of 39 cases, a vegetal foreign body was not identified on CT, but in seven it was found at surgery (25%) Resolution of clinical signs was achieved in 11 of 11 cases when a vegetal foreign body was identified on CT and in 26 of 28 cases without a foreign body identified Two cases of recurrence were observed in animals in which no foreign body was detected. (5%) resolution of clinical signs after a single surgical procedure in 95% of the cases Although CT sensitivity in detecting VFB was moderate, it allowed for precise visualisation of the extent and localisation of the abscesses consider use of intra-op ultrasound

Question 57

Endoscopic treatment of acute oropharyngeal stick injuries in dogs: 46 cases (2010-2020) Kilduff-Taylor 2023

Answer 57

Retrospective analysis injury tracts were explored using 0° and 30° forward-oblique, 2.7 mm diameter, 18 cm length rigid endoscopes 38 (95.0%) had no major long-term complications. The remaining two dogs developed cervical abscessation after endoscopy, one of which resolved after repeat endoscopy and the other resolved after open surgery.

Question 58

Histologic evaluation of mandibular and medial retropharyngeal lymph nodes during staging of oral malignant melanoma and squamous cell carcinoma in dogs Grimes 2019

Answer 58

Retrospective multi-institutional study. ANIMALS 27 dogs with OMM and 21 dogs with OSCC. Prevalence of lymph node metastasis OMM (10/27 [37%]) and OSCC (6/21 [29%]). Distant metastasis was identified in 11 (41%) dogs with OMM The MRLN was affected in 13 of 16 dogs with lymph node metastasis Metastasis contralateral to the primary tumor in 4 of 17 dogs that underwent contralateral lymph node removal. bilateral lymphadenectomy of the MLN and MRLN lymphocentra is recommended for such dogs It is also possible that the presence or absence of lymph node metastasis may be a poor predictor of distant metastasis because metastatic patterns are subject to interindividual variation and are seldom straightforward

Question 59

Mickelson 2020 – canine tonsillar neoplasia and tonsillar metastasis | VCO

Answer 59

- primary neoplasms: SCC 55%, lymphoma 17%, melanoma 12% - 92% of neoplasms malignant - metastasis: 9% of tonsillar neoplasia 25/41 melanoma, 10/41 carcinoma, 2/41 hemangiosarcoma 1/41 fibrosarcoma, malignant histiocytosis, basal cell tumour and sarcoma - tonsillar melanoma: 28/53 primary, 25/53 metastatic from distant primary - 9/53 concurrent LN metastasis - indirect contrast lymphangiography → no lymphatics draining to palatine tonsil - likely hematogenous spread to tonsils