Mandibulectomy and Maxillectomy Flashcards
Maxillectomy and mandibulectomy are what type of procedure? (clean etc?)
Clean contaminated
Why is surgical infection rate rare? (2)
Rich vascular supply
Prescence of saliva
What local analgesia agent?
- onset time?
- Action length?
Bupivacaine (0.5 – 1 ml, 0.5%)
- 8-30 mins
- lasts: 4-10hr
Which LA block blocks the following:
- Rostral maxilla?
Intraorbital
Which LA block blocks the following:
Body of mandible for more extensive sx?
mandibular nerve block near the mandibular foramen
Which LA block blocks the following:
Rostral mandible
mental foramen block
Which LA block blocks the following:
Entire maxilla
maxillary nerve block
For the maxillary nerve block, the needle is introduced where?
Rostral to the ramus and ventral to the zygomatic arch, just caudal to the lateral canthus of the eye.
How to control bleeding? (5)
Electrocautery,
Ice cold saline,
gelatin sponges,
bone wax
local application of epinephrine
When performing a mandibulectomy, ligation of what a. is needed?
Inferior alveolar a.
When performing a maxillectomy, ligation of what a. is needed? (2)
major palatine artery or infraorbital artery
Significant haemorrhage is expected with maxillectomy; why?
Nasal cavity is often entered, significant turbinate haemorrhage
Temporary or permanent occlusion of what a. may be required in a caudal maxillectomy?
Temporary or permanent carotid artery
How to position for:
Central and caudal maxillectomy
Oblique lateral recumbency
How to position for:
Segmental removal of body or ramus of mandible
Lateral recumbency
How to position for:
Bilateral rostral mandibulectomy and rostral maxillectomy
Dorsal recumbency
What should be placed to improve visualisation?
Mouth gag
Where should bone be cut in relation to teeth? and how far from tumours?
Between teeth roots.
1cm from tumours.
What teeth are involved with Rostral mandibulectomy?
Excision of bone including some or all incisors and one or more canine teeth.
Define Central mandibulectomy
Removal of a segment of one mandibular body.
Define Caudal mandibulectomy
Removal of all or a portion of ramus.
Define Total hemimandibulectomy
Removal form the symphysis including all of one body and the ramus.
Define three quarter mandibulectomy
Removal of one hemimandible and the rostral portion of the other hemimandible.
Define Pre-maxillectomy
Removal of the bone surrounding the incisors (may include the nasal planum).
Define Rostral hemimaxillectomy
Removal of the bone surrounding the canines and incisors.
Define Central hemimaxillectomy
Removal of the bone surrounding the pre-molars.
Define Caudal hemimaxillectomy
Removal of the bone surrounding the molars. This may include the zygomatic arch and the bone of the ventral orbit.
How to position for rostral mandibulectomy or lateral recumbency for segmental hemimandibulectomy?
Position the patient in dorsal recumbency
Rostral and central mandibulectomy;
Where is gingiva incised?
The gingiva is incised 0.5 cm beyond the level of planned bone transection and is elevated from the bone using a periosteal elevator, preserving a cuff of gingival tissue for closure.
What 3 attachements are transected in Rostral and central mandibulectomy; to give the 1cm margins?
Oral mucosa, labial mucosa and muscular attachments
How to control haemorrhage in Rostral and central mandibulectomy
Electrocautery
Rostral and central mandibulectomy;
A) How to transect bone? (3)
B) How to split longitudinally
A) n oscillating saw, air drill or burr
B) Osteotome
Rostral and central mandibulectomy;
What artery is ligated/cauterised?
Inferior alveolar a.
Rostral and central mandibulectomy;
How to split the symphysis
Osteotome
How to close Rostral and central mandibulectomy? Including skin
Closure is achieved by suturing labial mucosa to the gingival and sublingual mucosa.
Following rostral mandibulectomy, the skin can be sutured directly to the sublingual mucosa.
Caudal mandibulectomy and hemimandibulectomy
How to position
Lateral
Caudal mandibulectomy and hemimandibulectomy
What incision may help improve exposure?
A full-thickness incision in the cheek from the commissure to the level of the caudal border of the ramus may help improve exposure.
Caudal mandibulectomy and hemimandibulectomy
What removal facilitates visualisation of the dorsal ramus and TMJ and is necessary if it is involved in the pathology.
Zygomatic arch
How to replace zygomatic arch in Caudal mandibulectomy and hemimandibulectomy? Is this needed?
Stabilisation with orthopaedic wire
Not necc; more for post op cosmesis
Caudal mandibulectomy and hemimandibulectomy;
Soft tissues are transected at least 1 cm from the edges of the tumour. What muscles (4) and capsule (1) does this include?
masseter, digastricus, temporalis and pterygoid muscles and the TMJ capsule.
Caudal mandibulectomy and hemimandibulectomy;
What vessel is ligated and where?
The inferior alveolar artery is ligated and transected at the mandibular foramen.
Caudal mandibulectomy and hemimandibulectomy;
Mucosa closure?
For closure, the labial mucosa is sutured to the gingival and sublingual mucosa.
Caudal mandibulectomy and hemimandibulectomy;
How to suture to prevent the tongue hanging out the mouth?
The commissure of the lip can be advanced to the level of PM1 or 2
When is Mandibular rim excision appropriate?
For tumours that do not invade the ventral cortical bone and that lie next to the pre-molars or molars
Rostral and central maxillectomy
How to position?
Oblique lateral
Rostral and central maxillectomy;
What 3 structures need to be incised at the site of transection?
Labial mucosa
Gingiva
Palate
Does the major palate a. and infraorbtal a. need to be ligated in a central or rostral maxillectomy?
Central
Rostral and central maxillectomy
What is used for bone resection; why this?
Osteotome; bone is thin
Rostral and central maxillectomy; its challenging to control bleeding until what is fully removed?
Maxillary segment
What osteotomy should be left until the end to minimise bleeding with Rostral and central maxillectomy?
Caudal
How to suture mucosa in Rostral and central maxillectomy? What flap might be needed?
Labial mucosa suture to gingival and palatine mucosa
Dorsally based labial advancement flap.
What can be used to reduce breakdown of dorsally based labial advancement flaps?
Pre-placing drill holes into the hard palate and suturing through these
Rostral and central maxillectomy
How to prevent drooping of noce?
dorsal cartilage can be sutured via drill holes in the nasal bone
Rostral maxillectomy
How far from tumour is incision?
1cm
Caudal maxillectomy
How to position?
Oblique lateral
Caudal maxillectomy
Where is the cheek incised to increase exposure?
From the commissure to the caudal border of the ramus to increase exposure.
What incision will improve exposure of the dorsal osteotomy site, ventral orbit and zygomatic arch with Caudal maxillectomy?
Dorsolateral
What 3 structures are incised with Caudal maxillectomy?
Labial, gingival and palatine
Caudal maxillectomy; what osteotomy is left util the end to reduce haemorrhage?
caudal osteotomy is left until last to allow ligation of the major palatine a
When can food/water be introduced after surgery?
day after soft for 10-14 d
What should be avoided chewing after?
Hard food
Chew toys
Wat tube should be placed in any cat that is undergoing a mandibulectomy or maxillectomy procedure?
Oesophagostomy
What may occur following maxillectomy, if the patient is asymptomatic monitoring may be appropriate, otherwise repair is recommended?
Oro nasal fistula
What may occur during mandibulectomy or maxillectomy. If tooth death occurs, extraction may be required?
Tooth root damage
When may the tongue may fall to one side, potentially increasing the rate of drooling (2)
Following hemimandibulectomy or rostral mandibulectomy
Mandibular drift may also follow a?
hemimandibulectomy
Mandibular drift usually have no problems; but when is it a problem and what helps?
canine tooth impinges on the hard palate. Extraction or crown reduction of the canine tooth may improve signs associated with this.
What may be used to prevent drift?
Orthodontic chains from the canine tooth of the intact mandible running to the ipsilateral fourth pre-molar
In dogs, removal of what length of both mandibular bodies may have difficulty with prehension of food in the initial stages, but usually adapt over time.
At least half
Removal of both mandibular bodies means what for feeding?
hand feeding for life
