Oral Surgery Flashcards
What lip is most commonly affected by labial avulsion? Why is it a difficult fix?
shearing trauma from lower lip
avulses alon the mucogingival line, leaving very little soft tissue for reattachment
How does recovery from maxillary and mandibular labial avulsions compare?
suture reconstruction is easier with maxillary labial avulsions because the lip naturally hangs down and will not be fighting gravity with the weight of the lip like with the mandibular lip
What can be done to better treat mandibular labial avulsions?
interdental stent sutures with wire or prolene at the mucogingival junction can help anchor the lip to the bone and ease tension
What layer should be apposed first for lip reconstructions and cheiloplasties?
mucousal (then deep tissue and skin)
What are the 3 options for lip reconstructions?
- direct apposition
- labial advancement flap
- labial rotation flap
What are the 3 general steps to a cheiloplasty?
- excise lip margins to the level of the second premolar
- appose the incised lip margins from oral mucosa, muscle, connective tissue, and skin
- improve cosmesis by excising redundant skin from one or more indicated sites
What are the 2 main surgical techniques for treating cleft palates? What artery needs to be preserved?
- overlapping flap technique - make an incision and flip oral mucosa over the cleft
- sliding bipedicle flap repair - 2 pairs of incisions on either side of the cleft, meet at the middle
(epithelium will grow over exposed hard palate)
palatine artery
What is involved in a primary cleft? How is it repaired?
lip, premaxilla, nostril
create mucosal flaps to separate nasal cavity from oral cavity
What are 3 common causes of acquired palatal defects?
- dental disease where deep maxillary periodontal pockets progress to the apex of the tooth, lysing bone
- trauma - foreign body lodged between dental arcade
- surgery complication
What are 4 causes of the increased rate of dehiscence in oronasal fistula surgery?
- saliva
- tension
- motion
- cautery
What layer takes part in the double-layer flap technique used in oronasal fistula surgery?
buccal mucosa
What are the most common causes of mucoceles and salivary gland enlargement?
MUCOCELES - trauma, sialoadenitis, sialoliths clog
ENLARGEMENT - canine necrotizing sialometaplasia, adenocarcinoma
What adenocarcinomas commonly cause salivary gland enlargement in dogs and cats?
DOGS = parotid
CATS = mandibular
Why is it not recommended to drain or tap salivary glands for mucoceles?
increases chance of infection
(one tap for diagnosis is okay)
What are the 4 major salivary glands in dogs? Which one has 2 divisions?
- parotid
- mandibular
- sublingual - monostomatic (3 cm rostral), polystomatic (small, independent lobules open directly into oral cavity)
- zygomatic
How do feline salivary glands compare to canine ones?
cats have an additional major salivary gland - molar
What is commonly seen upon physical examination with salivary mucoceles?
- fluctuant swelling
- swollen/enlarged nonpainful gland; may be painful if in an acute inflammatory stage or secondary infections
What are salivary mucoceles? What breeds are overrepresented?
subcutaneous accumulation of saliva within a nonepithelial, nonsecretory lining
- German Shepherds
- Poodles
What salivary gland is most commonly affected by mucoceles?
sublingual —> mandibular too closely related and is commonly also removed
What are 3 common clinical presentations for salivary mucoceles?
- cervical mucocele*
- pharyngeal mucocele —> respiratory distress
- ranula
How are salivary mucoceles most commonly treated?
surgical removal of the involved gland +/- percutaneous aspiration of accumulated saliva
How are ranulas and pharyngeal mucoceles treated?
RANULA = marsupialization, common in high risk patients, but not done with primary or idiopathic ranulas
PHARYNGEAL = lanced to relieve respiratory distress prior to definitive surgery
What are the steps in excising mandibular and sublingual salivary glands for mucocele treatment?
- an oblique horizontal incision is made on the ventrum of the mandible
- the mandibular and sublingual salivary glands are exposed and passed over the digastricus muscle, if size allows
What 2 actions need to be avoided when excising the mandibular and sublingual salivary glands?
- NO vertical incision - limits exposure of gland adenectomy
- avoid cutting the digastricus
When is a drain placement indicated for mandibular and sublingual salivary gland excision?
is a mucocele cannot be adequately drained during surgery
What are the 3 most common causes of mucocele recurrence after mandibular/sublingual gland resection?
- failure to remove enough of the polystomatic sublingual gland*
- operation of wrong side
- removed from structure
What are the most common oral tumors in dogs anc cats?
DOGS - malignant melanoma, SCC, fibrosarcoma
CATS - SCC
What is the most common malignant oral tumor? In what animals are they overrepresented?
oral melanoma
- males > females
- small breeds
- pigmented mucosa
What are the general trends for melanoma malignancy?
- mucocutaneous and nail bed = MALIGNANT
- haired skin = BENIGN
How do oral melanomas act?
locally invasive (destructive and lytic) with early metastasis to regional lymph nodes and lungs
gingiva > labial and buccal mucosa > palate > tongue
Amelanotic melanoma:
What is the most common treatment of oral melanomas? What should be done with this treatment?
local control by surgical resection
biopsy the 3 regional lymph nodes that drain into the oral cavity: mandibular, parotid, retropharyngeal
What 2 other treatments are commonly done in conjunction to surgical resections of oral melanomas?
- radiation (also palliative for nonresectable tumors)
- immunotherapy - vaccine approved
What is the prognosis for oral melanoma resection? What affects prognosis? What is the main goal in most cases?
poor for achieving cure
tumor size, lymph node status, first surgery
palliation of clinical signs
How does the prognosis of SCC vary with location?
the further caudal in the mouth, the worse the prognosis (less likely to be noticed, harder total removal)
nontonsillar > tonsillar
What are the most common locations of nontonsillar SCC? How do they act?
gingiva and tongue
locally invasive, ulcerated, friable, and slower to metastasize to lymph nodes
What is the most common treatments for tonsillar SCC? What metronomic therapy is used?
- surgical resection
- radiation therapy
- chemotherapy
Piroxicam - NSAIDs slow tumor growth by blocking angiogenesis
What is a tonsillectomy? What are 4 common reasons to perform this surgery?
removal of the palatine tonsil
- airway obstruction
- dysphagia
- unresponsive tonsillitis
- neoplasia - SCC, lymphosarcoma
How does tonsillar SCC commonly act?
highly malignant with early metastasis to distant sites by the time of diagnosis
What are the 4 types of glossectomies?
- partial - involves free tongue
- subtotal - entire free tongue and part of genioglossus and geniohyoideous
- near total - greater than 75%
- total - 100%
What are the 2 most common places to find oral SCC in cats? What involvement is common?
gingiva and under tongue
extensive bone involvement with early advancement before diagnosis is made
What is the prognosis of SCC in cats like?
guarded to poor —> results with surgery is not as good compared to dogs (tumors more advanced by time of diagnosis, making clean margins more difficult to achieve), radiation commonly causes significant side effects
(photodynamic therapy, chemotherapy)
In what animals are oral fibrosarcomas most common? Where are they most commonly found?
large breed dogs
gingiva > palate > labial or buccal mucosa > tongue, maxilla caudal to canine tooth
What is the most common biological behavior of oral fibrosaromas? How does this compare in older and younger dogs?
locally invasive with distant metastasis later in course
- OLDER = slow-growing, less frequently ulcerated
- YOUNGER = very aggressive
What variant of oral fibrosarcomas are seen? Where are they most commonly found?
histologically low-grade, biologically high-grade
maxilla (extraoral)
How does local recurrence of oral fibrosarcomas compare to melanomas and SCC?
more common in dogs due to the increased chances of dirty margins due to tumors extending beyond the apparent edge of the tumor
What are peripheral odontogenic fibromas? How are they treated?
benign proliferation of fibrous connective tissue, which may contain isolated islands of odontogenic epithelium
local excision with small segment of bone
Where do acanthomatous ameloblastomas arise from? What do they commonly contain? How do they act?
remnants of dental laminar epithelium
islands or sheets of squamous epithelium in fibrous connective tissue stroma
benign, but locally invasive to bone
What are the 2 most common odontogenic tumors?
- central ameloblastoma
- odontoma
What are central ameloblastomas? What do they arise from? What do they commonly look like?
noninductive odontogenic tumors where mesenchyme is not stimulated to produce dental hard tissues
dental laminar epithelium
cystic or multiloculated with considerable bone destruction
Ameloblastoma:
- bone loss at root
- soft tissue swelling
What are odontomas? What are the 2 types?
inductive odontogenic tumor where mesenchyme is induced to produce dental hard tissues
- COMPOUND - contain tooth structures in various stages of development
- COMPLEX - dental tissues not differentiated enough to resemble teeth
Odontoma:
mineralization
What are undifferentiated malignant oral tumors? What is the prognosis like?
HIGHLY AGGRESSIVE tumors common in younger dogs with rapid growth and early metastasis commonly found on the maxilla caudal to canine teeth
poor - survival is often one month or less with poor response to any treatment
What are the most common clinical signs of oral tumors?
- external swelling
- loose teeth*
- pain
- periorbital swelling and exophthalmos (far back, deep)
What are the 6 types of mandibulectomies?
- unilateral
- bilateral
- central
- total (including joint)
- caudal
- 3/4
What are the 2 types of total mandibulectomy? What common complication following surgery should be remembered?
- TOTAL - hemimandibulectomy including ramus
- SUBTOTAL - vertical ramus left
mandibular drift of remaining half can cause trauma to the palatal mucosa due to the remaining canine
How can exposure of the mandible be facilitated for mandibulectomies?
incising through the lip commissure
How is the lip commissure closed following a mandibulectomy? Why?
the commissure is shortened by excising the mucocutaneous junction from the level of the 2nd premolar to the original lip commissure
improves ability to prehend food and drink water and prevents tongue lolling on that side
How does a maxillectomy compare to a mandibulectomy? What equipment is commonly used?
typically associated with more hemorrhage, especially if nasal turbinates are affected
power equipment = faster and easier, especially more caudally
What postoperative care is recommended following mandibulectomies and maxillectomies? When is a feeding tube necessary?
- IV fluids for first 24 hours
- pain medications
- most animals will be able to drink and eat within 24 hours
worries of dehiscence
What are the 4 most common mandibulectomy complications?
- swelling, especially pseudoranulas under the tongue
- wound dehiscence more common rostrally
- mandibular drifting (“clicking” sounds when jaw is closed)
- those caudal to 4th premolar and 3/4 mandibulectomies aill significantly affect ability to prehend food
What are the 2 most common maxillectomy complications?
- wond dehiscence with oronasal fistula
- bilateral rostral maxillectomy allows for nose to droop and affect prehension
