The Tooth the "Hole" Tooth and Nothing But the Tooth
Being a tooth is hard. You get gnashed and ground on a regular basis. You get attacked by bacteria. Sometimes your own cells eat away at you, creating holes.
Many cats have holes in their teeth. “Tooth resorption” is the term for holey teeth, and it differs from cavities in that it is not caused by bacterial decay. A resorptive lesion is caused by cells called odontoclasts eating away at the tooth. A tooth with a cavity softens and may turn brownish; a tooth with a resorptive lesion appears white and solid, except for what looks like a jagged hole usually starting near the gumline. This hole often fills in with gingival tissue, making it red.
Many different species get resorptive lesions, including humans, dogs, horses and cats, but in veterinary medicine, the cat’s lesions are the most prevalent and notorious. Interestingly enough, big cats in the wild also get resorptive lesions, although to a lesser degree than domesticated cats. One study in Namibia found these lesions in cheetahs, leopards, caracals, lions and African wildcats. While 20 to 50 percent of domestic cats have resorptive lesions, only about 16 percent of the wild cats had these lesions. Another study of wild Eurasian lynxes found no resorptive lesions at all.
No one knows what causes tooth resorption. In humans, a history of trauma or wearing braces is correlated with tooth resorption. This does not seem to be a major factor in the cat. Some studies suggest that diets supplemented with too much vitamin D may play a role.
Hole in One, Look Under the Gum
Cats that have resorptive lesions in one tooth often have them in other teeth. Some lesions can be seen while others are hidden below the gum. Resorption announces its presence by pain. Imagine the pulp in your teeth being exposed to temperature differences, salt, moisture, dryness or poking. It’s extremely painful, and the cat may stop eating, eat on only one side of the mouth or salivate. Even under anesthesia, a cat might react to probing of the lesion; his jaw may chatter, or he might jerk his head slightly.
Because some cats are more stoic and don’t show any signs at all, veterinary dentists recommend radiographs on all teeth of cats presented for dental work. Radiographs will expose a hidden resorptive lesion.
Chewing Over the Options
How does one treat a tooth with resorptive lesions? Dentists on the human side may attempt filling or restoring the lesion, but this is not always successful. In many cases, they must extract the tooth. With cats, affected teeth are extracted most of the time, thus removing the source of pain and potential infection. Many of the teeth break during extraction, because they are partially eaten away. Removing the remaining root fragment can be difficult; hence, the notorious reputation of these lesions.
Radiographs help make the decision to extract. In some cases, if the tooth root has fused into the surrounding jawbone, the top of the tooth is amputated instead of the entire tooth being removed.
Happy Teeth, Happy Cat
Teeth have hard lives. They get resorbed. They get extracted. They get amputated. It’s hard to say how many angry and painful teeth result in grumpy and anti-social cats, but knowing a little about resorptive lesions may help us understand the possible connection. Keep your cat happy by staying vigilant for signs of problems and seeking regular dental care.