Ear Teeth

Todayโ€™s path rounds are on ๐ž๐š๐ซ ๐ญ๐ž๐ž๐ญ๐ก, more scientifically known as ๐๐ž๐ง๐ญ๐ข๐ ๐ž๐ซ๐จ๐ฎ๐ฌ ๐œ๐ฒ๐ฌ๐ญ๐ฌ!

๐–๐ก๐š๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐ƒ๐ž๐ง๐ญ๐ข๐ ๐ž๐ซ๐จ๐ฎ๐ฌ ๐œ๐ฒ๐ฌ๐ญ๐ฌ are a form of ๐ก๐ž๐ญ๐ž๐ซ๐จ๐ญ๐จ๐ฉ๐ข๐œ ๐ฉ๐จ๐ฅ๐ฒ๐จ๐๐จ๐ง๐ญ๐ข๐š, which is a fancy term for an extra tooth or teeth in a location outside of the normal dental arcade. Ear teeth, as the name suggests, tend to be found close to the base of the ear!

๐–๐ก๐จ ๐ ๐ž๐ญ๐ฌ ๐ข๐ญ?
Horses most commonly get this condition.

๐–๐ก๐š๐ญ ๐œ๐š๐ฎ๐ฌ๐ž๐ฌ ๐ข๐ญ?
Ear teeth form during embryonic development, when a cystic structure that would normally disappear as the embryo grows ends up being retained in the fully developed animal. This structure contains nests of cells that are part of tooth development, so as the animal continues to develop, one or more teeth form within the cyst. Weird!

๐–๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐š ๐ฉ๐ซ๐จ๐›๐ฅ๐ž๐ฆ?
Generally these teeth donโ€™t cause any issues, however the cystic structure that contains them can sometimes form a ๐Ÿ๐ข๐ฌ๐ญ๐ฎ๐ฅ๐š (draining tract) to the skin surface. This hole can sometimes ooze fluid, which disturbs owners and can impact the aesthetics of the animal.

๐‡๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐š๐ ๐ง๐จ๐ฌ๐ž๐?
The best method of diagnosis is taking an X-ray of the skull to identify teeth in a location where teeth should not be! That X-ray, combined with the clinical signs and history, confirms the diagnosis of a dentigerous cyst.

๐‡๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐ž๐š๐ญ๐ž๐?
While most owners choose to leave these cysts alone, some owners will want them removed. These cysts can be removed surgically with great success, and the horse can resume its horsey life free of a toothy ear.

๐๐ก๐จ๐ญ๐จ๐ฌ
1-2) Two examples of the fistulas of dentigerous cysts oozing fluid. Gross.
3) A cool X-ray where they put probes into the fistulas of a horse with two dentigerous cysts, so you can see the probes following the fistula right to the weird teeth!4) A dentigerous cyst on a cross-section of the head.
5) A dentigerous cyst after being removed from the head, showing the teeth that grew!

๐’๐จ๐ฎ๐ซ๐œ๐ž๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโ€™s Pathology of Domestic Animals, Volume 2. Sixth Edition.
Barakzai SZ, Dixon PM. Dentigerous Cysts. Equine Veterinary Education 2012;24(11):579-581.
Smith LCR, Zedler ST, Gester S, Keane SE, Goodwin W, van Eps AW. Bilateral dentigerous cysts (heterotopic polyodontia) in a yearling Standardbred colt. Equine Veterinary Education 2012;24(11):575-578.

Photos 1-2 ยฉ LCR Smith et al.
Photo 3 ยฉ SZ Barakzai et al.
Photos 4-5 ยฉ Noahโ€™s Arkive contributor King licensed under CC BY-SA 4.0.

Leave a Reply