Mandibulectomy and Maxillectomy Flashcards
Why is cautery and laser therapy advised to be used sparingly?
Incisions with diathermy or laser can increase the risk of wound dehiscence
Where cautery is required, can you think of a way to limit damage to the surrounding tissues and vasculature?
If electrocautery is required, it is best applied with bipolar forceps (avoiding monopolar cautery) to limit the effect on surrounding tissues and decrease vascular damage.
What are the different types of Mandibulectomies and maxillectomies? (5)
unilateral
bilateral
rostral
lateral/segmental,
caudal.
What recumbency is most commonly used for surgery?
Lateral
What positioning is very useful for resections of the rostral and lateral aspects of the Maxilla?
Dorsal recumb
Dorsal recumbency allows good access to what parts of mandible?
Caudal
What approach is used for For caudal Maxillectomies?
A combined intraoral and dorsolateral approach
Which recumbency, with the head elevated and the maxilla suspended between intravenous poles secured to the ceiling can be useful for mandibulectomies?
Sternal
What is cut during a mandibulectomy for a tumour removal?
soft tissues (laterally and medially), and the bone is cut on both sides of the tumour without touching the actual tumour
Define rim excision mandibulectomy
partial segmental excision leaving the ventral border of the mandible intact.
Define A total or unilateral mandibulectomy
complete excision of one of the mandibles. In some literature this is less accurately referred to as “hemi-mandibulectomy”.
Define A bilateral rostral mandibulectomy
The rostral parts of both mandibles are removed after an osteotomy between the second and third premolars. If necessary, the osteotomy can be performed as far caudally as between the fourth premolars and first molars.
Define In a unilateral rostral mandibulectomy,
only the part of the bone that carries the three incisors, canine, and first and second premolars is removed. This is indicated for a small tumour not crossing the mandibular symphysis.
Define a caudal mandibulectomy,
the ramus of the mandible (including the condylar and coronoid processes) is removed.
Define segmental mandibulectomy,
a full thickness part of the midsection of the mandible is excised.
What is a rim excision?
The excision of only the dorsal two thirds of the mandible, leaving the mandibular canal and the ventral cortex intact
When is a rim incision indicated? (2)
- wide excision of small and minimally invasive tumours on the alveolar margin;
- marginal excision of benign lesions, such as a small benign odontogenic tumours.
Steps for a rim excision.
1.After mucoperiosteal incision, the soft tissues are subperiosteally elevated (ventrally) away from the planned ostectomy site.
2. At the level of the attached gingiva, the soft tissue incision must be narrower than the bony incision to be able to cover the bone tension-free with gingiva on completion of the procedure.
3. The ostectomy is performed in an interdental space. A surgical handpiece combined with an osteotomy burr or an oscillating saw or a TPLO saw are the instruments of choice.
4.The bone margins may have to be smoothed.
5. The attached gingiva and alveolar mucosa are sutured over the bony defect.
Rim excision:
At the level of the attached gingiva, the soft tissue incision must be ??? than the bony incision to be able to cover the bone tension-free with gingiva on completion of the procedure.
narrower
Rim excision - where is the ostectomy performed?
Interdental space
What must happen to bone margins in a rim excision?
Smoothed.
What is excised with a unilateral rostral mandibulectomy?
incisors, canine, first and second premolars in the dog.
Why is An osteotomy between the canine tooth and the first premolar or between the first and second premolar teeth
not indicated?
because this would transect the alveolus and root of the canine tooth.
Why is a unilateral rostral mandibulectomy rarely indicated for oncology?
10mm surgical margin; proximity of mandibular symphysis
