Tooth Resorption
Tooth resorption (TR) occurs when an animal's tooth is attacked by its own body and undergoes disintegration. Tooth resorption may start anywhere on the tooth, above or below the gumline. TR occurs in many animals, but most commonly in cats. Tooth resorption in cats was previously called feline odontoclastic resorptive lesions (FORLs), cervical line lesion, neck lesions, and feline caries. The most common teeth affected with TR are the upper fourth premolars, the lower third premolars, and the lower first molars.
The cause of tooth resorption is unknown. It is important to note that this process is very different than what happens with caries (cavities) which are caused by bacteria. Proposed causes that have been investigated include viral and bacterial disease, nutrition, and hereditary and environmental influences.
Detailed examination and dental radiographs (x-rays) are the best way to diagnose tooth resorption. Sometimes, TR is obvious with visual examination. A red, fleshy lesion at the gum line (seen above left) or degradation on the tooth itself can sometimes be seen on visual exam. However, when TR is below the gumline, dental radiographs may be necessary to diagnose the location and type of TR. Pictured to the left, a cat tooth shows resorption of the tooth root (circled) only on x-rays. The tooth otherwise appeared normal.
Treatment depends on the type, severity, and location of the TR. Regardless, treatment is aimed at removing the source of pain that can occur during the resorptive process. Previous treatment involving sealing the lesion with a restorative have fallen out of favor since this does not provide proper long-term treatment. Often times, extraction of the affected tooth is the treatment of choice. In some cases, part of the root has already been incorporated into the surrounding bone. In this case, any portion of the tooth that can be extracted should be. This procedure is often called crown amputation with intentional root retention.
