Principles of Maxillofacial Oncologic Diagnostics and Surgery

Introduction
Oral tumors are common in cats and dogs. They may be of dental (odontogenic) or non-dental origin. In dogs, peripheral odontogenic fibroma, acanthomatous ameloblastoma, malignant melanoma, squamous cell carcinoma and fibrosarcoma are most commonly diagnosed in the mouth. In cats, the predominant oral tumors are squamous cell carcinoma and fibrosarcoma.

Geriatric patients are generally predisposed to oral tumors, but there are certain tumors (e.g., fibrosarcoma) that occur more frequently in young, large-breed dogs. Papillary squamous cell carcinoma, viral papillomatosis and undifferentiated malignancies are also more likely to occur in young dogs. Male dogs may be at higher risk for malignant melanoma and fibrosarcoma. Large breed dogs have a higher incidence of fibrosarcoma and nontonsillar squamous cell carcinoma, while small breeds have a higher incidence of malignant melanoma and tonsillar squamous cell carcinoma. Dogs with heavily pigmented oral mucosa are often predisposed to malignant melanoma.

Benign Lesions
Enlargement of the gingiva is often due to gingival hyperplasia (an increase in the number of normal cells in a normal arrangement) and may result from chronic or acute inflammatory disease. Gingival enlargement is also caused after administration of anticonvulsants, cyclosporine and calcium channel blockers. Gingivectomy and gingivoplasty are performed to remove excess gingiva.

A periapical cyst can develop when scattered epithelial cells within the periodontal ligament proliferate after chronic irritation of the apical periodontal ligament from pulpitis or pulp necrosis. If such a tooth is extracted without removing the cyst lining around the root apex, a residual cyst remains. Similarly an apical (tooth root) abscess can develop when pulp infection and inflammation spread through the apical foramina into the periapical tissues. Treatment is tooth extraction or root canal therapy.  [...]