The Mandible and Maxilla

Question 1

Cat vs dog - who tolerates mandibulectomy/maxillectomy more?

Answer 1

Dog

Question 2

What are the 4 components of the mandible?

Answer 2

Right and left half – hemi-mandible

Horizontal component – body

Vertical component – ramus.

Question 3

What joins the two halves of the madible at the rostral aspect?

Answer 3

Fibrous symphysis

Question 4

The vascular supply to the mandible comes from? A branch of what?

Answer 4

inferior alveolar artery, a branch of maxillary artery.

Question 5

Where dos the inferior alveolar a. enter the mandible? Travel and exit?

Answer 5

This enters through the mandibular foramen on the medial aspect of angle of the mandible, travels rostrally within the marrow cavity of the mandible and exits laterally through the mental foramen just caudal to the canine tooth

Question 6

Which artery must be cauterised or ligated and transected during mandibulectomy?

Answer 6

mandibular artery

Question 7

What provides sensory innervation to the mandible and lower teeth?

Answer 7

mandibular nerve (a branch of trigeminal)

Question 8

How does the mandibular nerve (a branch of trigeminal) course? and change?

Answer 8

entering at the mandibular foramen, coursing rostrally as the inferior alveolar nerve through the marrow cavity and exiting at the mental foramen as the mental nerve.

Question 9

The ducts of the mandibular and sublingual salivary glands run where in relation to the body of the mandible

Answer 9

medial

Question 10

The ducts of the mandibular and sublingual salivary glands open where?

Answer 10

Sublingual papilla

Question 11

What happens if you transect The ducts of the mandibular and sublingual salivary glands during mandibulectomy?

Answer 11

Not a concern

Question 12

3 bones of the maxilla?

Answer 12

Maxillary
Incisive (premaxilla)
Nasal

Question 13

What teeth are containe in the:
A) Maxillary bone?
B) Incisive bone?

Answer 13

A) Canines, premolars, molars
B) Incisors

Question 14

The vascular supply of the maxilla comes from branches of?

Answer 14

Maxilary artery

Question 15

Where does the major palatine a. run ?

Answer 15

Through the caudal nasal cavity and caudal portion of the hard palate before running rostrally, ventral to hard palate, midway between the midline and the maxillary teeth.

Question 16

Where does the infraorbital a. run, pass and exit?

Answer 16

Runs through the caudal nasal cavity dorsal to the major palatine artery, passing through the maxillary foramen and infraorbital canal of the maxilla, exiting at the infraorbital foramen just rostral to the carnassial tooth.

Question 17

Which vessels may be ligated/transected in a maxxilectomy?

Answer 17

Both the major palatine artery and the infraorbital artery

Question 18

The nerve supply to the maxilla is from the ? that supplies the teeth?

Answer 18

infraorbital nerve (a branch of the maxillary nerve)

Question 19

Where will the infraorbital a. be transected in a maxillectomy?

Answer 19

within the infraorbital foramen

Question 20

The parotid salivary gland duct terminates where?

Answer 20

At a papilla just lateral to the fourth upper pre-molar tooth and the zygomatic salivary ducts terminate just caudal to this

Question 21

T or F
These ducts can be transected without concern during maxillectomy.

Answer 21

true

Question 22

Where does Digastricus run from and to?

Answer 22

Runs from the occipital region of skull to the ventral border of the body of the mandible

Question 23

Where does the Masseter run from and to?

Answer 23

Runs from the zygomatic arch to the lateral surface of the caudal body and ramus of the mandible

Question 24

Where does the Pterygoideus (A lateral and medial muscle ) run from and to?

Answer 24

run from the pterygoid, sphenoid and palatine bones to the angular process of the ramus

Question 25

Where does the Temporalis run from and to?

Answer 25

Extends from the temporal region to the dorsal ramus

Question 26

What is the function of the digastricus?

Answer 26

Open the jaw

Question 27

What is the function of the Masseter and Temporalis?

Answer 27

Close the jaw

Question 28

What is the function of the Pterygoideus?

Answer 28

Close the jaw and pull to the side for chewing

Question 29

he most frequently occurring oral tumours in dogs are? (6 in order)..

Answer 29

1. malignant melanomas, 2. non-tonsillar squamous cell carcinomas, 3. fibrosarcomas, 4. osteosarcomas, 5. canine acanthomatous ameloblastomas 6. fibrous/ossifying epulides

Question 30

Malignant melanoma: A) Age? B) Breed size? C) Colour of growth? D) Met rate? E) Met location?

Answer 30

A) Older B) Small breed C) Often dark, 33% amelanotic D) 80% E) LN; not just ipsilateral side!

Question 31

Squamous cell carcinoma (non-tonsillar): A) Age? B) Breed size? C) Appearance? D) Met rate? E) Met location?

Answer 31

A) Older B) Large C) Flat, ulcerated, minimally external D) 20% E) Local

Question 32

Fibrosarcoma: A) Age? B) Breed size? C) Breed? (2) D) Arise from? E) Met rate? F) Met location? G) What anatomy is commonly involved?

Answer 32

A) Middle age- Older B) Large C) Labrador + golden retriever D) Gingiva near maxillary carnassial E) 35% F) Local G) Hard palate

Question 33

Osteosarcoma: A) Breed size? B) (Origin? (2) C) Met location?

Answer 33

A) Medium + Large B) Maxillary and mandibular C) Lung

Question 34

Do axial osteosarcomas vs appendicular osteosarcoma have a better prognosis post-operatively?

Answer 34

axial osteosarcomas

Question 35

Canine acanthomatous ameloblastoma (CAA): A) Breed size? B) Arise from what epithelium? C) Met? D) Invade? E) Oten arise from the rostral mandible or maxilla, what happens 2ry to this? F) Tx of choice?

Answer 35

A) Medium - large B) Odontogenic C) No! D) Locally E) Displace incisors F) mandibulectomy/maxillectomy.

Question 36

Fibromatous epulides arise from?

Answer 36

Peridontal ligament

Question 37

Epulis arise from?

Answer 37

Gingiva

Question 38

Fibrous/ossifying epulides are often located where?

Answer 38

Pre-maxillary

Question 39

Fibrous/ossifying epulides; Local excision without bone removal often provides excellent local control but likelihood of cure is improved if?

Answer 39

if the tooth and a small margin of the alveolar bone is removed with an air drill.

Question 40

Which of these are more commonly seen in older, small-breed dogs? Osteosarcoma Fibrosarcoma Malignant melanoma

Answer 40

Malignant melanoma

Question 41

What is involved in pre op staging of oral tumours?

Answer 41

Thorax image - radiograph vs cT Pre op biopsy (deep into lesion) LN asessment; ideally mandibular, parotid, retropharyngeal nodes bilaterally

Question 42

What is the issue of using x rays to visualise oral tumours?

Answer 42

Often under-estimate the degree of bony involvement due to the delay in lysis appearing radiographically

Question 43

T or F Pre-operative biopsy is useful to determine the degree of resection required.

Answer 43

True

Question 44

T or F Compared to MRI, CT is superior to assess tumour bone margins.

Answer 44

True

Question 45

T or F Optimal staging of oral tumour would include removal of mandibular and parotid nodes unilaterally.

Answer 45

Optimal staging would include removal of all three nodes (mandibular, parotid, and retropharyngeal) bilaterally.

Question 46

Follow-up intra-oral examinations should be performed every ? following surgery

Answer 46

3-4 months

Question 47

One year survival rates of 70-90% have been reported following aggressive surgical management of oral tumours, with reported recurrence rates ?

Answer 47

50%

Question 48

Do you know why caudally based tumours have a poorer prognosis in general? (2)

Answer 48

longer to notice them, more advanced at presentation

Question 49

Which tumours generally have the highest survival rates following surgical excision? (2)

Answer 49

Oral (non-tonsillar) SCC and acanthomatous ameloblastoma

Question 50

Why do fibrosarcoms have a higher recurrence rate? (2)

Answer 50

invasive Often located in the central or caudal maxilla

Question 51

Mean survival times for malignant melanoma?

Answer 51

1 year

Question 52

When is Radiation therapy (RT) is indicated indicated? (3)

Answer 52

high potential for local recurrence, - incomplete histologic margins, - large tumours - tumours located in the caudal oral cavity.

Question 53

How to access the nasopharynx and achieve biopsy samples or remove benign tumours? How to reduce risk of dehiscence and aid reconstruction?

Answer 53

Soft palate split through midline Leave distal aspect in tact

Question 54

Radiation therapy works better against microscopic disease so should be used pre or post op?

Answer 54

Post op

Question 55

Platinum-based chemotherapy (e.g., carboplatin) has been used to treat ? with a significant reduction in tumour volume reported.

Answer 55

malignant melanoma

Question 56

Most common feline oral tumour?

Answer 56

SCC

Question 57

SCC in cats usually arise from what mucosa? (2)

Answer 57

Gingiva Sublingual

Question 58

SCC in cats: A) How invasive? B) 20% met to? C) How common is distant met?

Answer 58

A) Highly B) LN C) Rare

Question 59

Most SCC in cats occur where?

Answer 59

Caudal to canines

Question 60

Maxillary SCC masses in cats invade where?

Answer 60

Periocular

Question 61

Tongue SCC masses in cats invade where?

Answer 61

Sublingually

Question 62

Advanced imaging is particularly recommended in cats SCC. Why?

Answer 62

Highly invasive; often extend within the medulla of the mandibular bone far beyond their gross limits

Question 63

After what % of mandible is excised, long-term inappetence is a concern in cats?

Answer 63

50%

Question 64

Feeding tubes should be placed following mandibulectomy in cats; why?

Answer 64

Often do now eat!