Dr. Ignacio Durall Rivas
TRAUMA OF VARIOUS ORIGIN
Oral cavity is exposed to chemical abrasion, electrical burns, foreign bodies-specially bone fragments within the mandibular or maxillary dental arcades-, tongue necrosis caused by pine caterpillars (Thaumatopoea pityocampa) etc. Most of these conditions cause lip and tongue necrosis and even bone sequestration and communication between the oral and nasal cavities. Electrical burns should be specially considered because lesions appear after some days and, therefore, reconstructive surgery should be delayed.
PRIMARY AND SECONDARY PALATAL CLEFTS
Defects of the primary palate affect the lips and the rostral aspect of the palate whereas defects of the secondary palate affect the caudal aspect of the palate. Primary clefts can be unilateral or bilateral. They are congenital abnormalities and can be caused by some medicines, radiation, etc. Primary palate clefts are primarily an esthetical problem because they do not affect growing. On the other hand, secondary palate clefts need special care because the abnormal communication between the oral and nasal cavities impedes puppy suckling and correct nutrition. If left untreated, puppies can die.
Longitudinal palate fractures are commonly seen in cats after falling from excessive heights and are usually similar to congenital palatal clefts.
Classical treatment of secondary palate clefts includes the overlapping flap technique making an incision in the palatal mucosa, parallel to the dental arcade, that allows to elevate the palatal mucosal flap and to suture it to the medial aspect in a tensionless manner. Palatine arteries should be preserved. Most treatment failures are caused by tension and suture dehiscence. We do believe that suture pattern and suture materials are not important because the author has tried different combinations with no detectable differences. Another technique to be used when the defect is wide is bilateral labial flap transposition. It requires a previous bilateral premolar extraction and central partial bilateral maxillectomy. It has been successfully used with two patients.
NEOPLASMS OF THE ORAL CAVITY
Malignant melanoma, squamous cell carcinoma and fibrosarcoma are the malignancies diagnosed most often in dogs by the author.
Melanoma has the worst prognosis and high likelihood of metastasis when the dog is presented to the veterinarian. None of our patients has survived more than 1 year. Wide and radical surgical excision, i.e., maxillectomies and mandibulectomies, has not been effective in controlling the disease.
Fibrosarcoma is a better candidate to radical surgical excision because of its lower metastatic rates. Local recurrence is very common if excision is not performed in a radical manner.
Cryotherapy has been successfully used to treat squamous cell carcinomas, with only a few recurrences after two years. Cryosurgery is a good therapeutic option because the ice ball can reach areas of alveolar bone and destroy malignant cells that could not be found using other methods and could be the cause of local recurrence.
Epulides are benign tumours commonly found in Boxers. They appear to be predisposed because prevalence in Boxers older than 5-years-old is over 30%. Gingivectomy of the visible portion must be done every two to three years as it usually results in recurrence. Malocclusion, calculus and molar incorrect positioning can be involved in its aetiology.
Oral papillomas in young animals are virus-induced and usually affect all littermates. The incubation period is 30 days. They are caused by a papovavirus and usually regress spontaneously within 3 months once immunity develops.