A common feline oral malady is feline oral resorptive lesion (FORL). A majority of the cats affected are older than 4 years. These tooth defects have also been called cavities, neck lesions, external or internal root resorptions, and cervical line erosions. The location of a FORL is usually at the surface of the cemento-enamel junction (CEJ) where the free gingiva meets the tooth surface. The most common teeth affected are the maxillary third and fourth premolars and the lower third premolar and first molars; however, FORLs can be found on any tooth. The etiology is unknown, but theories supporting an autoimmune response mediating cellular and humoral factors, calicivirus, and metabolic imbalances relating to calcium regulation have been proposed.
Patients affected with FORLs may show hypersalivation, oral bleeding, or have difficulty eating. A majority of affected cats do not show obvious clinical signs. Most times it is up to the clinician to diagnose the lesions on oral examination. Diagnostic aids include a periodontal probe or cotton tipped applicator applied to the suspected FORL. The lesion often erodes into the sensitive dentin, causing the cat to show pain with jaw spasms when the EOR is touched. Intraoral radiology is helpful in making definitive diagnosis and treatment planning.
The FORL can present in many stages: Initially (Stage I) an enamel defect is noted. The lesion is usually minimally sensitive in because it has not entered the dentin. Therapy of this defect usually involves thorough cleaning, polishing, and frequent (every 3 months) application of fluoride cavity varnish. In Stage II, lesions penetrate the enamel and dentin. These teeth may be treated with self cured or light cured glass ionomer restoratives, which release fluoride ions to desensitize the exposed dentin, strengthen the enamel, and chemically bind to tooth surfaces. The long term (greater than 2 years) effectiveness of restoration of Stage II lesions have not been proven. Glass ionomer application to the FORL does not automatically stop the progression or the disease. Intraoral radiography is essential to determine if the lesions have entered the pulp chamber (Stage III) requiring either endodontics or extraction. These teeth should not be filled and left alone.
Radiographic appearance of FORLs vary from minute radiolucent defects of the tooth at the cemento-enamel junction, to internal resorption and ankylosis of the apex to the supporting bone In Stage IV FORL, the crown has been eroded or fractured. Gingiva grows over the root fragments, leaving a sometimes painful bleeding lesion upon probing. Treatment of choice is flap surgery and extraction of the root fragments if they appear inflamed or painful to the patient.
Cats can also be affected by stomatitis, referred to as lymphocytic plasmacytic gingivitis pharangitis syndrome. The etiology of this disease has not been determined. An immune related cause is suspected due to the large amount of plasma cells on histopathology. Gingival signs in an affected cat include dysphagia, weight loss, and ptyalism. Oral examination abnormalities include cobble stone-like hyperplasia and hyperemia on the glossopalatine and palatopharyngeal arches, soft palate, and oropharynx. In addition, marked gingivitis and periodontitis exists around the premolars and molars. Intraoral radiographs often reveal moderate to severe periodontal disease with marked supportive bone loss. All stages of feline oral resorptive lesions can also be apparent clinically and radiographically.
Traditional therapy options include thorough cleaning and polishing, gingivectomy, extractions corticosteroids, gold therapy, Flagyl, megesrol acetate, and laser care. An effective approach to diagnosis and care is to first check for feline leukemia, immunodeficiency virus, chemical profile, and urinalysis for metabolic abnormalities.
Next intraoral radiographs are taken of all the teeth and gingival areas of missing teeth. With the radiographic findings, each tooth can then be examined and treated individually. If a tooth is affected by moderate to severe periodontitis typified by greater than 90% bone loss, it should be extracted. In addition, all root fragments need to be removed. Radiographs should be repeated after extraction to ensure complete tooth removal. Immediately following surgery, prednisone ( l mg/lb) is given daily and tapered over a 3 week period. The client is advised and shown how to daily brush their cat's teeth followed by irrigation with .2% chlorhexidine. If these diagnostics and treatments do not work within 2 months, then all teeth are removed distal to the canines. If this still does not relieve the inflammation, then all the teeth distal to the canines are extracted. In some cases all the teeth including the canines and incisors are extracted for positive results to occur.
Cats are also effected by oral neoplasia. Squamous cell carcinoma (SCC) is the most prevalent type of oral cancer. SCC can arise from the oral epithelium and is characterized by local extension and invasion. Morbidity and mortality come from local disease rather than distant metastasis. Less common feline oral malignancies include melanoma, fibrosarcoma, lymphosarcoma, and undifferentiated carcinomas.
Not all feline oral swellings are malignant. Cats are frequently affected by treatable oral foreign body granulomatous reactions, osteomyelitis arising from dental disease, eosinophilic granulomas, mycotic infections, and nasopharyngeal polyps. Biopsies are essential in that the clinical appearance of malignancy can be deceiving.
Some cats have orthodontic problems. Commonly a lance or saber-like projection of the maxillary canines occur, especially in Persians. Cats are also affected with wry bites that are typified as uneven on the right and left sides of the mandible and/or maxilla.
Dr. Jan Bellows is a board-certified veterinary dentist. His office, All Pets Dental Clinic, is located at 9111 Taft Street in Pembroke Pines, Florida. He can be reached for consultations at 954-432-1111.
Date Published: 6/27/2002 2:14:00 PM
Date Revised: 01/31/2004