Ch 89 Maxillectomy/Mandibulectomy Flashcards
Grimes JAVMA 2019
Histologic evaluation of mandibular and medial
retropharyngeal lymph nodes during staging of oral
malignant melanoma and squamous cell carcinoma in dogs
27 dogs with OMM and 21 dogs with OSCC.
RESULTS
Prevalence of lymph node metastasis did not differ significantly between dogs with OMM (10/27 [37%]) and dogs with OSCC (6/21 [29%]).
Distant metastasis was identified in 11 (41%) dogs with OMM and was suspected in 1 dog with OSCC.
The MRLN was affected in 13 of 16 dogs with lymph node metastasis, and 3 of those dogs had metastasis to the MRLN without concurrent metastasis to an MLN.
Metastasis was identified in lymph nodes contralateral to the primary tumor in 4 of 17 dogs that underwent contralateral lymph node removal.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated histologic evaluation of only 1 MLN was insufficient to definitively rule out lymph node metastasis in dogs with OMM or OSCC; therefore, bilateral lymphadenectomy of the MLN and MRLN lymphocentra is recommended for such dogs.
Soukup JAVMA 2020
The canine furcation cyst, a newly defined
odontogenic cyst in dogs: 20 cases (2013–2017)
RESULTS Mean body weight and age of affected dogs were 23.5 kg (51.7 lb) and 8.2 years, respectively.
All 20 dogs had a unilateral cyst, with the right (n = 13) or left (7) maxillary fourth premolar tooth affected and viable in all dogs.
A predominant clinical sign was a fluctuant swelling of the buccal gingiva and mucosa overlying the CFC, and enucleation of the cyst lining, with or without extraction of the affected tooth, resolved the lesion in most dogs.
CONCLUSIONS AND CLINICAL RELEVANCE Our findings indicated that CFC is an odontogenic cyst of uncertain etiopathogenesis and that complete evaluation of the clinical, radiographic, and histologic features of the lesion in affected patients is necessary to distinguish a CFC from other odontogenic cysts and tumors in dogs.
Defining CFCs in terms of characteristic features permits accurate diagnosis and appropriate treatment of these previously unclassifiable odontogenic cysts in dogs.
Cray JAVMA 2021
Analysis of risk factors associated with complications
following mandibulectomy and maxillectomy in dogs
459 client-owned dogs that underwent a mandibulectomy or maxillectomy between January 1, 2007, and January 1, 2018.
RESULTS
271 complications occurred in 171 of 459 (37.3%) dogs.
Of 253 complications, most were considered minor (157/253 [62.1%]).
increased surgical time had a significant (OR, 1.36; 95% CI, 1.12 to 1.54) association with the occurrence of ≥ 1 complication. For each additional hour of surgery, the odds of complications increased by 36%.
Preoperative radiation therapy or chemotherapy increased the odds of incisional dehiscence or oral fistula formation (OR, 3.0; 95% CI, 1.3 to 7.2).
Additionally, undergoing maxillectomy, compared with mandibulectomy, increased the odds of incisional dehiscence or oral fistula formation (OR, 1.8; 95% CI, 1.1 to 3.1).
Two hundred forty-four of 271 (90.0%) complications occurred in the perioperative period (0 to 3 months after surgery).
CONCLUSIONS AND CLINICAL RELEVANCE Compared with mandibulectomy, performing maxillectomy increased the risk for incisional dehiscence or oral fistula formation. Mandibulectomy and maxillectomy had a moderate risk for a complication.
Boston Vet Surg 2020
Outcomes of eight cats with oral neoplasia treated with radical
mandibulectomy
Animals: Eight cats were included. Methods:
Results: Ages ranged from 8 to 17 years. All cats had 75% to 90% of the mandible removed and feeding tubes placed.
Seven cats had squamous cell carcinoma, and one cat had a giant cell tumor.
Six cats ate on their own postoperatively.
Three cats had local recurrence and tumor-related died at 136 and 291 days.
Six cats had no recurrence, with survival times of 156, 465, 608, and 1023 days, and two cats were still alive at 316 and 461 days after surgery.
The three long-term survivors died of causes unrelated to oral neoplasia.
One cat died at 156 days due to aspiration of food material. (had ulcerative esophagitis from feeding tube which may have reduced esophageal motility)
The overall estimated mean survival time was 712 days.
Conclusion: After radical mandibulectomy, independent food intake was achieved in 6 of eight cats, and four cats lived longer than one year. Clinical significance: Radical mandibulectomy should be considered for the treatment of extensive oral neoplasia in cats. Successful long-term outcomes are possible with aggressive supportive care perioperatively.
Harvey JFMS 2022
Feline maxillary sarcoma:
clinicopathologic features
of spindle cell sarcomas
from the maxilla of 25 cats
Case series summary Feline maxillary sarcomas are aggressive spindle cell neoplasms that occur within the maxilla, palate and upper lip of cats. This diagnosis includes fibrosarcoma and sarcomas with indeterminate histomorphology, excluding melanocytic tumors and sarcomas that can be differentiated by histomorphology.
In this study of feline maxillary sarcomas in 25 cats, the cats’ ages ranged from 4 to 16 years (median 12.5).
These sarcomas presented as smooth thickenings or mass lesions of the gingiva and palate, often involving both the right and left quadrants of the maxilla. Radiographic bone loss was typically absent to mild at the time of diagnosis.
Histologically, feline maxillary sarcomas were composed of spindle cells with varying amounts of fibrous stroma and mild inflammation.
Metastasis was not documented for any cat in the study, although clinical staging was limited. Cats were often euthanized because of local recurrence following incomplete tumor excision and local tumor progression. Median survival time from the date of histologic diagnosis was 70 days (n = 12).
Carroll JSAP 2023
Random mucosal rotating flaps for rostral to mid maxillary defect reconstruction: 26 dogs (2000-2019)
Twenty-six client-owned dogs were retrospectively included.
Twenty-three dogs underwent a single transposition or interpolation flap and three dogs were treated with a double transposition flap.
Postoperative complications, including dehiscence or flap necrosis, occurred in six dogs.
Clinical Significance: Random mucosal rotating (transposition or interpolation) flaps are versatile when used to close rostral maxillary defects in dogs. Postoperative complications appear to be more likely when these flaps are used to close mid maxillary defects.
K Carroll JAVMA 2020
Tumor size as a predictor of lymphatic invasion
in oral melanomas of dogs
To investigate putative associations between oral melanoma size and variables of histologic grade such as mitotic index, nuclear atypia, junctional activity, ulceration, lymphatic invasion, and degree of pigmentation.
SAMPLE 59 samples of oral melanomas from dogs sourced from 6 diagnostic laboratories within Australia.
RESULTS
A significant relationship was identified between the size of oral melanomas and a single variable of histologic grade, lymphatic invasion, with **larger tumors more likely to show lymphatic invasion. **
Further analysis revealed 2 applicable size thresholds for different clinical scenarios.
**Results indicated lymphatic invasion can confidently be ruled out for tumors < 6.5 mm in diameter (100% sensitivity) and ruled in for tumors ≥ 24.5 mm in diameter (100% specificity). **
CONCLUSIONS AND CLINICAL RELEVANCE An association was found for oral melanomas of dogs between tumor size and lymphatic invasion.
Ambridge JSAP 2023
Clinicopathologic features of canine peripheral odontogenic fibromas and risk factors for laboratory diagnosis
Sharma Vet Surg 2021
Survival time of juvenile dogs with oral squamous cell
carcinoma treated with surgery alone: A Veterinary Society
of Surgical Oncology retrospective study
No dogs had mets or recurrence of disease
All surgical margins were clean
The median follow-up time was 1556 days (92 to 4234 days). All dogs were alive at the last follow-up except for one documented
death, due to dilated cardiomyopathy.
Median disease-specific survival time
was not reached.
Conclusion: The prognosis after wide surgical excision of OSCC in juvenile
dogs was excellent.
Clinical significance: OSCC in juvenile dogs can be effectively treated with
surgery alone.
Villamizar-Martinez JFMS 2021
Comparison of unilateral rostral,
middle and caudal segmental
mandibulectomies as an
alternative treatment for unilateral
temporomandibular joint ankylosis
in cats: an ex vivo study
Objectives Temporomandibular joint ankylosis (TMJA) is the partial or complete inability to open the mouth due to intra- or extra-articular fibrous, bony or fibro-osseous tissue proliferation. Surgical procedures such as gap arthroplasty, condylectomy or wide extra-articular osteotomy have been recommended to treat this condition; these techniques are challenging, time-consuming and have been occasionally associated with postoperative recurrence, severe periarticular neurovascular iatrogenic trauma and death. Segmental mandibulectomy had previously been recommended as an alternative option for unilateral TMJA, but the location of mandibulectomy and extent of bone removal from the mandible region have not been mentioned in the literature. This study aimed to validate the area of the mandibular body (rostral, middle or caudal) and amount of bony tissue that should be osteotomized during a segmental mandibulectomy for treatment of unilateral TMJA in cats. Methods In this block study, 30 cadaver heads of domestic shorthair cats were randomly divided into three groups of 10 specimens each based on the mandibular region that would undergo segmental mandibulectomy (rostral, middle and caudal). The size of the removed mandibular segment and pre- and postoperative vertical range of mandibular motion were compared for statistical purposes. Results A significant statistical difference was observed between the pre- and postoperative vertical range of mandibular motion between the rostral, middle and caudal segmental mandibulectomies (P <0.001). The mean postoperative recovered range of mandibular motion for the rostral, middle and caudal segmental mandibulectomies was 50.4%, 81.9% and 90.4%, respectively. Conclusions and relevance The caudal segmental mandibulectomy showed the highest postoperative vertical range of mandibular motion. The removal of a minimum of 1.2 cm of the caudal mandibular body was required to achieve nearly full recovery of presurgical mouth opening in the specimens of this study. The caudal segmental mandibulectomy may eliminate the risk of iatrogenic periarticular neurovascular damage inherent to more invasive surgeries performed at the temporomandibular joint area. When performed unilaterally, the caudal segmental mandibulectomy is a viable surgical alternative that may show a similar outcome to other surgical techniques.
Villamizar-Martinez JFMS 2021
Comparison of unilateral rostral,
middle and caudal segmental
mandibulectomies as an
alternative treatment for unilateral
temporomandibular joint ankylosis
in cats: an ex vivo study
Caudal segmental mandibulectomy description
Warsaw JAVMA 2023
Piezosurgical bone-cutting technology reduces risk
of maxillectomy and mandibulectomy complications in dogs
41 maxillectomies and 57 mandibulectomies met the inclusion criteria (98 in total). Only 1 (1.02%) case was associated with excessive surgical bleeding requiring administration of blood products.
CLINICAL RELEVANCE
Results of this study show that intraoperative hemorrhage requiring the use of blood products during or immediately after a mandibulectomy or maxillectomy is rare when using a piezoelectric unit to perform osteotomies, and is substantially lower than that previously reported when using oscillating saws or other bone-cutting devices for maxillectomies.
