Intracranial trauma associated with extraction of a temporal ear tooth (dentigerous cyst) in a horse.

This research article describes a case where a surgical procedure to remove an abnormally located tooth (ectopic tooth) in a horse led to brain injury. The tooth was part of a condition known as heterotopic polyodontia. A second ectopic tooth was found compressing the right side of the horse’s brain during a post-mortem examination.

Understanding Heterotopic Polyodontia

In this study, the horse was found to have a condition known as heterotopic polyodontia. Key points about this condition include:

• It is characterized by the presence of extra or supernumerary teeth that are located outside their normal position, also known as ectopic teeth.
• In this particular case, the ectopic tooth was attached to the temporal bone, which forms part of the skull.
• Additionally, heterotopic polyodontia in this study was described as being typically associated with a sinus and a fistulous tract with a secreting membrane. This means that there was an abnormal pathway extending from the body surface to the ectopic tooth, with a membrane that was producing secretions.

Surgical Treatments and Complications

The study discussed the recommended treatment for heterotopic polyodontia, and the complications that arose. Key points include:

• The recommended treatment noted in the study was a complete excision of the tract, the dental component, and the lining of the cavity where the tooth was previously situated (the alveolar socket).
• However, during the surgical extraction of the ectopic tooth in this case, iatrogenic (caused by medical treatment or procedures) brain injury occurred. This was a complication that was not expected based on the recommended treatment strategy.

Post-Mortem Findings

The researchers conducted a post-mortem examination after the horse’s death. Important findings were:

• During the post-mortem examination, a second ectopic tooth was discovered.
• The second tooth was found to be compressing the right side of the cerebellum, a part of the brain which is responsible for motor control and several cognitive functions.

The study suggests that heterotopic polyodontia, though typically treatable, can present complications such as unexpected iatrogenic trauma. Additionally, the discovery of a second ectopic tooth during post-mortem underlines the importance of thorough pre-surgical assessments in such cases.