Feline Resorptive Lesions
External root resorption of teeth is one of the most common dental diseases of our feline patients. Some reports state 50-70% of cats have resorptive lesions. These “cat cavities” are called feline odontoclastic resorptive lesions based on the cells found lining these cavities that do not appear to be caused by decay and bacteria as in human cavities.
Why do some cats get it and others don’t?
The cause is unknown, but theories supporting an autoimmune response, calicivirus, and metabolic imbalances relating to calcium regulation have been proposed. The resorptive lesion often erodes into sensitive dentin, causing a cat to show pain and jaw spasms whenever the lesion is touched. Patients affected with FORLs may show increased salivation, oral bleeding, or difficulty eating. Most times, it is up to the veterinarian or astute owner to diagnose FORLs.
How do we treat it?
The aim of treatment is to relieve pain, prevent progression of tooth destruction, and restore function. It is believed that these lesions can be very painful when the lesion has eaten away the tooth crown and exposed the cavity to the oral cavity. Most affected cats do not show any signs; others may drool, chew with difficulty, or become reclusive or aggressive.
Currently there is no known treatment to stop the progression of these lesions. Treatment is aimed at preventing pain. There can be two types: type 1 is inflammatory and is best treated with extraction; type 2 involves roots that have already been resorbed to the jaw bone and is best treated with crown amputation with intentional root retention.
Trying to save these teeth with restoration of the enamel is only temporary and the restoration will eventually be lost as the cavity continues to enlarge. What is crown amputation? Often by the time these lesions are diagnosed, the extent of resorption is great: the root has been resorbed, or fused, and become part of the jaw bone and cannot be extracted. Studies indicate that these usually heal without incident and the body resorbs the tooth root. Annual prophy/dental cleanings and radiographs are recommended for cats that have been diagnosed with FORLs as cats tend to have more than 1 tooth affected over their lifetime.