Feline Odontoclastic Resorptive Lesions
Various studies have shown that Feline Odontoclastic Resorptive Lesions (FORL) have an incidence of over 25% in the general cat population and a significantly higher incidence in cats that are presented with other concurrent problems.
Fig 1 FORL affecting the lower third premolar in a cat
Radiograph of tooth in Fig 1 showing destruction of the crown and resorption of the distal root
Cats often present with symptoms of oral pain. Resorptive lesions may be visible on the crown(s) of affected teeth or they may be covered by hyperplastic reactive gingival granulation tissue. A combination of careful clinical and radiographic examination is required for accurate diagnosis.
Lower third premolar in a cat showing slight gingival hyperplasia with minimal inflammation affecting the disto-buccal aspect of the crown
Radiograph of the tooth in revealing significant destruction of distal crown not evident on clinical examination
FORLs are progressive lesions which will eventually lead to the loss of affected teeth. During this process there is usually significant inflammation of the periodontium and after the crown of the tooth is lost there may be persistent root remnants which can cause long term inflammation of the overlying gingival tissue.
Teeth with FORLs should be extracted and cats monitored for similar lesions affecting other teeth. Most teeth are extracted surgically and all should be radiographed preoperatively as there is often varying degrees of root resorption which will complicate the surgical procedure.
Atomisation of tooth roots is not an acceptable procedure because of the risk of damage to adjacent neurovascular structures and likelihood of leaving root remnants.