Tooth resorption is seen most often in the cat, but may occur in other species as well. Resorption is the process by which we lose our “baby” teeth—the root of a deciduous tooth is remodeled into bone, and then the crown of the tooth gets loose and comes out of the gum. Nobody knows why this process happens to perfectly good permanent teeth, but there are theories being studied including periodontal disease, abnormal chewing forces, and elevated levels of Vitamin D.
When resorption affects the tooth crown, it looks like an inflamed area of the gum growing over a part of the tooth. When resorption can be identified on oral examination, it is an indication for intraoral radiographic evaluation and treatment because there is pain and infection.
Complete extraction is the treatment of choice for teeth that have detectable crown resorption but no radiographic evidence of root resorption. Teeth with crown resorption but radiographic signs of advanced root resorption (and no concurrent periodontal disease, periapical periodontitis or stomatitis) may be treated by subgingival amputation, sometimes referred to as “intentional retention of resorbing root segments”. The thought is that if the root is already undergoing advanced resorption, then the remaining root remnants after crown removal may be expected to continue to resorb uneventfully.
Either form of treatment should be followed by gingival closure. If there is radiographic evidence of root resorption, but no clinical resorption can be detected on oral examination, it is currently thought not to be painful or prone to infection. The tooth can be “monitored” or preemptively extracted. Restoration of these teeth is not recommended. Semiannual dental examinations are recommended for all cats with previous diagnosis of tooth resorption. Radiography should be repeated annually or more frequently as dictated by the oral examination.